I've seen a ton of Tetris variants in my day, and Tetris'd is a wild one. It's not even a puzzle game: it's a platformer, with Tetris blocks as the platforms. You play a tiny, acrobatic person (a ninja, maybe?) who can jump and climb on the blocks as they fall, and the object is to survive for as long as possible without getting squished or falling off the board.

The controls are tricky: there are only arrows, a grab and climb button, and a button to jump onto a midair piece. Theoretically, you could get pretty high in the air by jumping up onto a series of falling blocks, but I found the controls a little too unresponsive to do that effectively. It's still a fun game, though, especially when you manage to pull off a clutch move to escape certain death. Like in real Tetris, pieces fall faster as the game goes on. Unlike in real Tetris, lines never clear, so you just have to keep climbing up and up and up ...

Every once in a while, someone actually sneaks something cool into the YouTubes. Tetris lovers of the world, unite!

via @arnteriksen

Stereogram Tetris needs a disclaimer: not everyone's going to be able to play this game, and those who can might get a headache from it. Remember those magic eye posters, where a secret image was revealed if you could unfocus your eyes the right way? This is Tetris inside one of those. If you can see the hidden 3D images, you can't even see where your pieces are.

I'm not sure it's healthy to stare at a stereogram for the length of time it takes to play a game of Tetris, but the game is definitely cool as a proof of concept. In case trying to play Tetris inside a magic eye isn't already hard enough for you, Stereogram Tetris has three skill levels. I haven't even come close to getting the 100 points it takes for a high score - I can see the stereogram, but not long enough to play a good game - but maybe some of you can do better.

Tetris-style games that involve arranging falling blocks have seen a lot of variations. Game-makers have tried adding odd pieces, weirdly-shaped game boards and bombs, just to name a few. In Equanimity, the twist is physics-based: the board is a balance beam, and you lose a life for every piece that falls off. The pieces don't interlock, though, like in Tetris. They're various geometric shapes, and you can clear them by matching three of the same color.

The challenge of Equanimity is that the tilting platform, combined with the shapes of some pieces, means that things don't always end up where you intended them to. It's not as fast-paced or challenging as Tetris, so perhaps the zen aesthetic of the game is appropriate. It's a way more relaxing way to kill time than watching your Tetris board fill up while you wait for that elusive long piece.

Today is a historic day. Not only is it the 65th anniversary of D-Day (and my grandfather, a US Naval Captain was there), It is the 25th anniversary of the greatest puzzle game of all time: Tetris. In honor of Alexey Pajitnov's awesome creation, I've tracked down some awesome ways to play Tetris on your PC or Mac -- for free.

Tetris 1989 (www.tetrisfriends.com) -- Although Tetris might have debuted in June of 1984, most of us were first introduced to this addictive puzzler in 1989 on a green and yellow tinged screen. As the pack-in game with the original Game Boy, Tetris was catapulted to a whole new audience of fans. Although we had Tetris (and Dr. Mario) for our NES, it wasn't until I got a Game Boy for Christmas in 1991 (third grade, baby!) that I really, really became Tetris-obsessed. You can revisit that nostalgia on your web browser in this Flash-based port, provided by Tetrisfriends.com (the official website for the Tetris.com rights holders). The original game music is even included! Tetrisfriends.com has a lot of other variations too, but the best, by far is Tetris 1989.

Quinn (OS X) -- Official variations for Tetris have been available for the Mac throughout Tetris's history, but the best native OS X iteration is Quinn, a tetromino game made specifically for OS X. You can even download special piece styles and backgrounds to make Quinn look more or less retro. Also, don't forget about the neat (if ultimately kludgy) implementation of Tetris included with emacs bundled in OS X.

The Original Tetris (MS-DOS, all 32-bit versions of Windows, including Windows 7) -- Developed a few days after the initial Electronica 60 prototype of the game, the MS-DOS port of the original game still exists, thanks to Vadim Gerasimov, whole helped create the port. His page discussing the development process for Tetris is an interesting read.

Tetrislight (Tetris for Silverlight) -- This is a neat Tetris implmentation using Silverlight rather than Flash. It's fun and the keyboard controls correlate to the old Microsoft Entertainment Pack of yore.

Quadra (Linux) -- There are lots of various Tetris-like games available for various Linux builds (Netris is a fun one), but I like Quadra because of its network support. It was also recently updated. Check out the Google Code page too!

David Friedman has a habit of posting clever ideas and concepts to his blog, Ironic Sans. Every once in a while, someone will take one of them and build a working model. That's what happened with Sirtet, a new kind of Tetris that's played one square at a time. It's an interesting idea, and it turns out it's a pretty good game, too.

If you're familiar with Tetris, you should have no trouble catching onto Sirtet. The object is to position your blocks so that you have 4 (but no more than 4) squares of a single color touching one another. Instead of building lines, as in Tetris, you're building Tetris pieces! When you connect 4, those blocks disappear and you get points. If you connect 5 or more, though, they turn to stone and become stuck on the board. That definitely adds a new level of challenge to the game, If you're a Tetris junkie, and the original version has gotten stale for you, give Sirtet a whirl.

[via Ironic Sans]

Wrapping your mind around a simple game like 99 Bricks is harder than you might imagine. The object of the game is to build the highest possible tower using only 99 pieces. Sounds easy enough, but you're playing with Tetris pieces and distinctly non-Tetris physics. If you screw up, you don't just leave gaps that you could have used to score points, you cause your whole tower to wobble and collapse.

Pieces also don't lock to a grid in 99 Bricks, the way they do in Tetris. You can wind up with pieces slanted diagonally, and there's an edge of the board that your toppled bricks can fall off of. 99 Bricks is kind of like Jenga, in that it's almost as satisfying to watch your tower crumble as it is to play seriously. Once you get the hang of the way the pieces behave, it's an addictive little game.

If you're a Mac user, did you know that Tetris comes with your Mac? Have a look through your Applications folder - you won't find it there. Thanks to Cory over at TUAW, I now know that Tetris is an Easter Egg that can be found in the Terminal application.

Here are the steps to get the game going:

1. Open Terminal, which you can find in the Utilities sub-folder in your Applications folder
2. In the Terminal window, type "emacs", then press Enter
3. Wait for the Emacs screen to load (you'll see a bunch of welcome information for GNU Emacs)
4. Press the Escape key, then type "x" then type "tetrix" (no space between "x" and "tetris") and press Enter

If you've followed the instructions exactly, you should now be looking at a working game of Tetris. Controlling the blocks is done with your arrow keys.

Yes, this game of tetris isn't the best implementation you will find. It's very narrow, making it quite frustrating to play. But hey - it's free Tetris, and it's built in to your Mac!

Quinn is a free Mac-style Tetris (ever heard of it?) clone with a few tricks up its sleeve. Aside from it's smooth, clean interface, Quinn offers customizable keyboard controls and downloadable custom backgrounds and piece styles.

Quinn's key feature is network multiplayer (via the Internet or locally through Bonjour), and there are multiple ways to determine a multiplayer winner: highest total score, highest score reached, longest play time, and most lines-per-minute.

When we checked the list of Quinn servers on the developer's site there were only 2 people playing on the Internet, so you may want to stick to networked Bonjour play with your office mates. If you are looking for strictly Internet-multiplayer Tetris, try Blockles.

Multi-player Tetris not your cup of tea? How about a shot of espresso then? Tetrical is an online Tetris-style game that adds a whole new dimension of complexity. Literally.

Tetrical is a browser based game that's basically a 3D version of Tetris. If you're pretty good at Tetris there is no guarantee you will be good at Tetrical, as it takes a while to get used to the 3D environment, And to make matters worse, some of your blocks have weird 3D shapes.

Of course, Tetrical is hardly the first 3D version of Tetris around. We remember playing Blockout back in the 80s. Fortunately, no classic game ever seems to go uncloned. If you're looking for a Blockout-style game to play in your web browser while your boss's back is turned, you might want to try 3DTRIS. The controls feel a bit more intuitive to us than Tetrical's, but that might be years of muscle memory kicking in.

[via Boing Boing]

Think you're pretty good at Tetris? Well playing against a computer is one thing, but how do you think you'd fare playing against other hard-core Tetris players? Blockles is an on-line competitive Tetris-clone from the makers of online dating site i'minlikewithyou. And it's the quickest way we're aware of to find out if you suck at Tetris.

Gameplay is pretty much exactly what you'd expect. You use the arrow keys to rotate blocks and hit the spacebar to drop them quickly to the bottom of the screen. You can either join a game hosted by another user or create your own if you're a registered user. Matches can have just a few players, or as many as 8.

There are a few interesting aspects to the multiplayer gameplay. For example if you break two or more lines apart at the same time, each of your competitors will get a new line of blocks. That makes Blockles a bit more fast-paced than the original Tetris game, but also a bit more addictive.

[via Silicon Alley Insider

Bloxorz is a game with a silly name, but great gameplay. While there are millions of puzzle games out there, few come close to matching the fun and challenge of Tetris. Though Bloxorz does.

Now, to be perfectly clear, Bloxorz is not a Tetris clone. In fact, the gameplay in Bloxorz couldn't be more different. The Tetris comparision is simply to point out that we think the game is that good, especially as a little web-based timewaster.

The hero of Bloxorz is, well, a rectangular block. Your job is to move the block by flipping it sideways or end-over-end through the maze of square tiles and arrange things so that your last flip slides your block through a single square hole. At first the game is a bit frustrating, but the learning curve is shallow and within 5 minutes you'll probably find yourself a few levels in, and having fun.

A few years ago you could impress friends by showing them a minesweeper clone on your PDA. These days, it's not unusual to see full-fledged PC or console games like Call of Duty 2 or Syberia ported to Windows Mobile.

But you don't have to spend a ton of money to turn your PDA into a gaming device. A few weeks ago we showed you five emulators that turn your Windows Mobile PDA into a pocket GameBoy or Playstation. This week, we showcase 10 great standalone games.

Solterra

First up is an amazing 3D space shooter called Solterra. This game is designed to run on Windows Mobile PDAs with an Intel 2700g graphics accelerator, so it's pretty much just for Dell Axim X50v/X51v users.

Solterra was developed as a commercial game, but later released as freeware. The rules are pretty simple. Fly your ship, blast anything that moves, and collect the thingamajigs you can pick up along the way to beef up your spaceships weapons and armor.

Tetris clones are a dime a dozen, but S-TRIS 2 is unique in two ways. One, it's free, and two, it's damn good. I found and tested it on my Pocket PC, but it turns out that S-TRIS 2 is available for a number of platforms, including Win32 (Windows), GP2X, Pocket PC, Smartphone, and Symbian. How cool is that?

In terms of game play value, S-TRIS 2 is right up there. The visuals are clean, quick and smooth, the sound effects are solid, and the controls feel responsive. It's a simple matter to remap the controls if you prefer a different layout - for example, I like to have the "fast drop" button be the center button on my keypad, and it took me all of about 15 seconds to make that happen. The game gracefully pauses if you have to turn the power off on your device, and starts up and shuts down relatively quickly.

S-TRIS 2 is definitely a keeper on my Pocket PC.

Although it's a little late for Easter, it's worth mentioning that the popular Bit-Torrent client uTorrent contains an Easter Egg on the About screen. Simply hitting the 'T' key on your keyboard while viewing the About window in uTorrent will show a very rudimentary but playable version of Tetris. Unfortunately, it doesn't appear to keep score or speed up as game play goes on, but it's definitely useful as a distraction when you need a moment to think.