Meganoid is a free (ad supported) platformer for Android that focuses on short, challenging levels with plenty of replay value. You're tasked with simply reaching the end of each level, but there's also diamonds to collect, baddies to kill and times to beat.

I'm not a huge fan of touch-screen d-pads, but Meganoid handles fairly well. It's got a great soundtrack, tons of levels, and a whole extra Sarge mode when you've managed to beat the first 70 areas. A great touch is the use of your OpenFeint friends list - if anyone has played the game, they will appear as bystanders in the background, and shout words of encouragement at you as you run by.

Really nice stuff, especially for free! Make sure you grab a copy, and watch out for the iPhone/iPad version coming soon.