Spirit HD is a weird game. It looks very much like an old school shooter in the vein of Asteroids and Tempest, but there's no fire button as you don’t actually shoot anything. Instead you draw circular force fields on the screen using your 'Spirit' space craft, and these are then used to suck in the bad guys that follow you around.
The tricky bit is that you'll need to dodge around the enemies to find the space to create the force field in the first place, while at the same time creating the fields in a position that will lure your enemies in. The graphics are quite simple, but look ace in a retro kind of way, and the game play becomes increasingly addictive the further into the game you progress.
Spirit HD isn't the most complex game in the world, but it looks great and its game play is surprisingly original and addictive.