Robokill: Titan Prime

Robokill means hot action, uncountable explosions and some really pain-inflicting guns. (in shoot em up, space, robot and action)

Play similar games:

Galaga This is the gametechnical version of going back to kindergarten and wonder why everything seemed so large back then.
Ether War Oldschool actionshooter with the right amount of special effects. Shoot first, ask never.
Space Pips De wildest Geometry War-ish action seen in a flashgame. Ever! Eliminate all enemies from space.