Radial Plus
Radial Plus is a unique little action game that was initially created for the Something Awful Game Dev Challenge. Although it may look like a typical arena shooter there is one cool twist with Radial Plus' gameplay. Instead of directly hitting the enemy to take them out, you would need to find a suitable angle and fire away before you can actually cause damage to the enemy ship.
It's amazing how one little shift in game rules can affect the entire game. This minor change in gameplay results in a creative and challenging game that requires you to think ahead of where your next shot will go.
Apart from this, the game is quite enthralling both in sound as well as in graphics. It's this little detail that makes this game worthy of your time.