The game is simple: shoot to the pink points to undress the girl, but keep an eye on the timer and the bullets!
There are 8 different levels with increasing difficulty. In challenging mode, beating a level unlocks the access to the next level, and the access to the same level in free mode. Moreover, every level has a three star rating that can be achieved by completing it with a certain amount of bullets and time remaining. Once completed all the three star rating levels, a bonus level will be unlocked, and here... Maybe it's better if you find out by yourself.