Monsters Vs. Alien - Gallaxhar Invades

You control B.O.B., the gelatinous hero from the movie, as he slides left and right along the bottom of the screen. Your job is to stop the descending rows of alien ships by firing a water cannon upward. The controls are simple, just arrow keys to move and the spacebar to shoot. You have to clear each wave of invaders before they reach the ground or overwhelm you with their own fire. The pace picks up as you advance, and the aliens start moving faster, making you weave between their shots. It feels like a quick, no-fuss arcade challenge that gets your fingers moving.