Escape From Puppy Death Factory is a game about rescuing puppies. It's also a game with a really clever switching mechanic that's nigh on impossible to explain in a succinct way. Plus, it's kind of a Metroid clone, and I love games that rip off Metroid!
The end result of this mash up is a fun platforming game that forces you to think your way through various different situations. Also you get to rescue puppies, which is a very good thing to do in general. Puppies deserve to be rescued.
Escape From Puppy Death Factory [Kongregate]