All of the info is here:
http://www.lexaloffle.com/voxatron.php - If you love Robotron, you will love this game.
This game is amazing if you love arcade-y action, trust me.
This game is still in Alpha, so please forgive the few bugs, and expect cool stuff in the future, like an enemy editor and a full adventure mode.
If you have made levels for this game, please share them.
And yes, I know this game has been out for quite some time, but I just discovered it... so yeah.