This game is a 2d Tower Defense, in a cartoon SF style. You have to destroy the bad robots before they come to your teleporter. For that, you can place towers, use spells. You can have help from you own robots (your protector).
Here is the map4 (level1) of the game Towerbots. You can see on this screenshot the protector, which is a robot who help you to destroy the ennemis (the bad robots).