I love twin stick shooters. I'm not good at them, but I love them. Sometimes I like to try and see how long I can survive without shooting, just for the hell of it. That's the mechanic that Omega Box is built on - avoiding the baddies, not shooting them.
In Omega Box you must pick up Plasma to survive. If you don't pick it up, you wil die. There are also a zillion other threats that will also kill you. Avoiding them whilst picking up the Plasma is the aim of the game and it's frantic.
Built into this is a simple combo mechanic - pick the plasma up quicker and you'll build up combos and increase your score. It's a well balanced risk/reward mechanic that works perfectly in this simple game.
My best score so far is 88,900. Let me see how quickly you can smash that!