If you're not familiar with the dual-stick shooter, then, well, there's really nothing to it. Let me break it down for you. There's two sticks, and you shoot things.

To break it down a little better than that, the left analog stick controls the movement of your character/vehicle, and the right stick controls the direction in which it's shooting. So your attacks and movement direction are totally independant of each other, making for some interesting tactics when you're taking down swarms of enemies flying at you. And swarms are exactly what come at you in retro evolved 2, in the form of miscellanious geometrical shapes. Each shape will behave differently... some just chill out where they are, some snake around the screen, and some chase you religiously - but run away from your shots. Some break apart when you hit them, some are surrounded by regenerating forcefields you have to break through, and others yet suck in surrounding objects and explode into frenzied particles - the list goes on.

The game itself never gets too complicated: you have to shoot these guys. But some modes might have you moving from one safe zone to another in order to keep shooting them, others might send them at you in waves. One favourite of mine is the sequence, that gives you different patterns of enemies in, well, a sequence. I've never made it to the end of the 20-stage sequence, but I've gotten really close...

More than anything I think retro evolved 2 proves you don't need a complicated game in order to give players an immersive experience. The simplicity of it is so addicting you can't help but be drawn into the frenzy.