The Spring Bundle is up but only for 2 more days as of this posting date and time.
This pack is actually quite good value for your money. Mostly, I wanted to post about Slydris, as it's the only one I've had time to play but it already feels very worth the asking price for the bundle. I can't vouch for the appropriateness of any of the other games in the pack as I've yet to play them myself and by the time I review them the bundle will more then likely be over.
Slydris, as you might have guessed from the name, is a tetris style block game. It's tetris roots are obveous, solid rows of blocks clear themselves off the field, you make chains to get more points, if the blocks reach the top row you will lose, and between each move gravity takes over causing all the blocks to fall. That's where the similarities stop however. The block types are only horizontal bars, and you have no control over the new ones falling into the playfield.
Instead, you can grab and slide any block on the field horizontally. After you slide a block and let go of it, gravity takes over and the blocks fall down. The idea of course is to slide blocks to cause rows to be filled all the way across, and thus cleared. It's a very simple mechanic and sounds boring on paper, but once you start playing you'll realize there is a great depth and even quite a bit of strategy to the game.
You also have a "powerup" that will charge up based on rows cleared and cascade length, called a 3 row bomb. As it's name implies, this powerup can be deployed to remove any three rows from the field. Very quickly each level starts adding other elements to the gameplay that all complement each other well. Some examples are the Stone blocks that cannot be shuffled but still fall down, magnet blocks that can be moved horizontally but once dropped into the playfield stay at the height they landed at, and "growth" blocks appearing from the bottom of the playfield that push everything stacked on them up one row.
The game has three modes. Endless should be considered the star "main mode" of the game. In Endless, you have infinite time to examine the grid of blocks and plan your move. The game will show you which blocks are being dropped into the field each "turn", so you can plan ahead. After each move, the blocks will drop as far as they can, the next row will drop into the field, and then it's your next move. Your progress is measured in rows cleared.
The other two modes are Survival and Zen. I haven't played them much yet, but basically, in Survival you have a set time limit to move any blocks you want before the next "wave" of multiple rows of junk blocks falls down. This creates a very different pace for the game, as the game shifts to "thinking fast" instead of planning well.
To contrast that mode, there is Zen, which basically keeps track of moves and rows while scrapping everything else, including score. You can't earn any of the in game achievements on Zen mode, so I'm guessing it's there to help you practice your mind to getting better at making chains without the pressure of getting a high score.
The music is pretty awesome, and the game has 3 tracks to play to labeled A, B, and C, as another throwback to the tetris game it clearly borrows from. All three are a mellow techno/trance that helps to match the thinking-over-action pace of the game.
One nice feature I noticed was the ability to save your game midway. If you quit playing a round on any of the modes, next time you pick that mode the "Continue" option will be lit up, letting you continue the game from where you left. This is actually a pretty good feature, because once you get rather decent at the game's basic mechanics, the game's length can be pretty long.
The game also allows up to 5 profiles on one computer, and will keep everyone's saves separate. This feature provides a much needed level of polish that a lot of short, independent casual games forget to add in.
In conclusion, I can highly recommend Slydris as a good block puzzle game. It's surprisingly original, yet it is not ashamed to be a fan of it's Tetris roots.
When the bundle ends, I will update this review with a link to where you can buy Slydris on it's own. For now you might as well buy it "on sale" in the bundle linked at the start of the post.