CatClimber is an adventure 2D platformer with cartoon graphics in which you have to defeat many enemies and find a way out of the dungeon. The game has 16 dungeon levels. Each level consists of several floors separated by brick walls. The game starts on the lowest floor. The player can use a pickaxe to break brick blocks, making his way to a higher floor. On the top floor, you need to find the key that opens the door to the next level. On the way, the player will encounter many monsters guarding the dungeon. These are spiders, bats, goblins and rats. To get to the top, you will have to fight them. There are also many traps on your way. Some of them are quite easy to overcome, and some will be quite difficult. On some levels, the key is guarded by a dragon, which attacks the player with fire projectiles. You need to take the key and dodge the dragon's attacks.

At each level you will encounter magic crystals. After collecting a certain number of crystals, you will receive a healing potion that will allow you to fully restore your health and successfully cope with all dangers. In the finale of the game, you will have to fight a dragon guarding your treasures and escape from the dungeon.