You've got less than 24hours to take advantage of the second Humble Bundle, so you should hop to it. I finally had a chance to sit down yesterday (as the tech news grinds to a holiday halt) and play the bundle's 5 games. So let me attest: as with the first Humble Bundle, there are some really great games here.

Cortex Command

I think you can tell a lot by a game's opening sequence: style, storyline. And certainly the only "story" you'll find in Cortex Command occurs here, as comic panels explain the humans have perfected "disembodiment" technology, shipping our brains off to colonize space. The art and the soundtrack (heavy on the Midi) give it a retro feel, and the gameplay itself -- mine and kill -- seems, at first glance, pretty simple. In Cortex Command, you're a disembodied brain, which you use to control your robot army. You're mining for resources, as is your opponent (either the CPU or up to 3 players), and so you have you use your army to destroy theirs, to infiltrate their bunker, and destroy their brain.

You have a well-stocked store at your disposal, full of weapons and tools that you can use to blast through walls/dirt/robots. And you can choose how these materials are delivered to you -- rocket delivery is cheap, but crashes and blasters have a good chance of destroying the cargo -- and even nearby robots. The physics of controlling all these elements -- ships, robots, gunfire -- are quite challenging, but the destruction you can wreak with Cortex Command is pretty fun.

The game is in beta, but has a lot of potential. I don't say that simply because the game -- quite good already -- is still in active development. Cortex Command also enables modding -- the game has built-in editors for you to make you own content -- and I think openness to fan creativity often bodes well for new games.

Braid

Braid looks and feels like arty version of Super Mario Brothers. Here, your character, Tim, is dressed a little more snazzily than that famed plumber; you've got a black suit, a red tie. The idea's similar: jump, jump, jump, dodge, rescue the princess. But only similar to a point. Tim has lost the princess because he's made a mistake, and the game's watercolor art and melancholy storyline emphasize loss, regret, forgiveness.

And Braid isn't simply a test of your "Mario skills." The game gives you the ability to rewind time, so if you fail to hit the space bar at the right moment, you can roll back time and try again. As you progress through the game, this time shifting becomes more complex -- on one level, you create bubbles that slow time, for example. Braid doesn't look to be terribly hard, as I was able to get past several levels and my Mario skills certainly aren't legion.

Osmos

Osmos offers a very different gaming experience than the spacebar spammiing of Braid or the click-and-fire of Cortex Command. It's a visually striking game that moves at what feels like a slower pace. In Osmos, you are a single-cell creature. Your only ability, propulsion. You steer yourself through this ambient world, aborbing smaller motes. But each time you actively propel yourself, you lose mass, and so the game requires a careful balance between floating and jetting, lest the mote you aim for suddenly is bigger than you. Collide with a larger mote, and it's game over.

Osmos has a electronica soundtrack that matches the feel of the game perfectly, and the game credits the artist each time a new track starts -- a nice touch. Like many of the games in this second Humble Bundle, Osmos has won multiple video game awards, including being selected by Apple as this year's iPad Game of the Year.

Revenge of the Titans

Revenge of the Titans had its official launch as part of the bundle, and Puppy Games has promised it will open source the game if the Humble Bundle breaks $1.75 million in sales. Revenge of the Titans is a tower defense game, which I confess having spent far too many hours on my iPad playing Plants vs Zombies, is one of my favorite genres.

Revenge of the Titans requires the usual tower defense strategy: balance offense, defense, and resources. There's plenty to keep you busy-- mining crystals and building turrets -- as you stave off the relentless alien armies. Super playable. Super fun. And, okay, I realize we're talking aliens, military commanders, and scientists here, but super cute.

Machinarium

It's no surprise, perhaps, that Machinarium is my favorite game in the bundle. The game was made by Amanita Design, the creators of Samorost 2, my favorite game in the first Humble Bundle. Machinarium shares the whimsical visuals and hand-drawn backgrounds characteristic of Amanita Design's games. And like Samorost 2, Machinarium is a puzzle-rich point-and-click adventure game. The player character is a robot, and you must explore his environment, trying to figure out what to click, what items can be moved and manipulated, what order items need to be activated.

I was able to finish Samorost 2 in fairly short order, but Machinarium offers a longer story. (I haven't completed the game yet; much like finishing a good novel, I sort of dread it.) The puzzles are just as challenging as ever. There are now hints and walkthroughs available in the upper right hand corner of the screen, but using them doesn't make Machinarium "easy mode" by any means. The walkthroughs are simply sketches of how to solve a puzzle in the vicinity, so they aren't necessarily spoilers -- or helpful.

Machinarium is delightful, just as a game should be.

And now that I've written this review, back to the game I go...