In Sid & Al, Tunnel catapulted the already addictive concept of The Incredible Machines into a whole new levels by injecting two hapless cartoon characters, a greedy cat a hungry mouse, as both puzzle pieces and colorful protagonists.
Animations are varied and superb (e.g. Sid & Al have different reactions to different food). The included puzzle designer is a welcome bonus. Don't be fooled by the easy beginning levels-- the "insane" levels are not called that for no reason