"UFO RAID" is a game where UFOs are coming to invade Earth; you have to tap your screen to drive them back.
If you fail to drive them back and they break through the red line that represents your final line of defense, its game over.
There are 4 different colors of UFO in the game.
If you destroy a lot of the same color in a row, you can rack up a higher score.
You also get more points for destroying UFOs that are close to your last line of defense.
If you destroy all of the UFOs in a stage, you can go on to the next one.
With each successive stage, there are more UFOs, they move faster, so the difficulty keeps going up.
You win when you clear the last stage, stage 30.
Try for a high score.