Rage always had good hand to action games, shooters or other genre games (but focused on fast action); both Incoming's, Mobile Forces, and what we are now interested most, Expendable.
Story, well, is almost non-existing. Another alien invasion and savior of the universe, bla bla bla... but I don't consider it as disadvantage. If this kind arcade shooter is enjoyable (Expandable is, very!) I simply don't care about story. I wan't explosions, many aliens to smash on walls and lot's of guns and ammo!
Main game objective in all missions is to walk through levels and kill anything what is moving, well almost. Sometimes you need to rescue some survivors. There is plenty weapons to collect, if you gather wapons of same type you get more ammo and weapon became more powerfull. Goood way to kill bosses faster, which are at end of level.
As you walk many funny things can happen like crashing plane, pillars falling over road etc.
Sounds are done very nicelly, explosions, gun noises or alien's sound, all on good level. Techno-style background music fits well to game also. Controls are easy to learn and easy to master.
Nice future in game is cooperative with 2 players on same screen.
When you play game you fell like on your own home arcade mashine!