Concept's pretty good. I do like the main mechanic of having to target specific people at the party and avoiding others - Though it seems a bit weird that butlers instantly lose the game. I assume it's because you get caught? - The presentation is also quite nice, I really love the sound design and how the song speeds up as you run out of time.
I do have a few issues with it, mostly that the balloon lasts too long and can hit a butler when already splashed onto the floor, and that it really feels like you should be able to get time back by hitting targets.
Other than that, game's pretty good. Definitely deserves to be expanded on in the future.