I just discovered Submachine over at eBaum's World. It's a fun and simple point and click game. A little internet search showed me that there's an extended version over at FreeGamePlayer (you'll just need to sit through a little ad while it loads). And that ArcadeTown has the game plus sequels: Submachine 2, Submachine 3, Submachine 4 and Submachine Zero. These versions are also downloadable.
I haven't played the sequels yet, but the first one was fun and fairly intuitive. If you want hints, just leave me a comment. But I think you should be able to figure this one out on your own.