This just in! Three iPhone games have been spotted by top scientists approaching the Earth from space! Estimated time of arrival is: now! Be on alert!

Just Half - Here's a game with an instruction manual embedded in its title. Just Half is a game about halving a rectangle. Use your finger to draw a line across the box, touching all orange points as you do. Make sure you keep the surface area on each side as equal as possible, as the game is remarkably picky about how accurate you are. Much, much more difficult than you would think, but also much more intriguing.

Denki Blocks! - A ten year old Game Boy Color puzzle game gets new life on the iTunes App Store! In Denki Blocks!, you slide patterns of "sticky blocks" around the board in an effort to join like colors together. Moving pieces of the massive block arrangement through tight spaces can be tricky, and getting through some of the most simple-looking puzzles can be quite a challenge. Denki Blocks! Free is also available.

Earth Defender - We've seen this situation before: aliens are attacking Earth, and only you, intrepid gamer, can save us! This new take on Missile Command utilizes the touch screen instead of slow missile attacks, allowing you to tap to take out enemies as well as launch bombs and execute other maneuvers. The aliens are crafty, though, and have different strengths, vulnerabilities, and levels of intelligence. A great-looking take on a classic arcade experience.

NOTE: Games listed may not be available outside of North America. Prices are subject to change and are therefore unlisted. Please see the individual game pages for purchasing info.