You should collect all spaceship parts on levels and reach the portal. But this is not so easy as it seems. Traps is everywhere. Mines, stakes trap, be careful to avoid all of them. And by the way look carefully for your clones, they can get on trap as well. The clones mimic all Cat movement, but they stop if they stuck on the wall. Avoid mines and enemies, and push the buttons to close the stakes traps.