T2B Escape 2
Ooh, I love T2B Escape 2! I very much enjoyed the first T2B Escape, and the sequel is just as well-crafted and charming as the original. All the room's elements (including a toy train, several mysterious cabinets and a bevy of cute animals) seamlessly synthesize into a series of intriguing but gratifyingly logical puzzles; to top it off, the graphics are nicely designed and pixel hunting is conspicuously absent. Perfect!
T2B does not have any sort of background story beyond the usual "trapped in a strange room for no apparent reason," but that doesn't really matter; the game is a satisfying exercise in quality room escape goodness and easily stands on its own merits. You're in for a treat: