I have made a lot of games in my time (granted it’s mostly just crappy FNaF fan games, so what do I know?) I obviously don’t expect a sprawling adventure from a game-jam game, I’ve participated in two in the past.
However, at least from my experience making game-jam games, four minutes is still pretty short, even for a week long game-jam. I think for a game like this, maybe seven to eight minutes should be good.
EDIT: I’ll play the game when I get the chance, although I don’t think it’ll really change my opinion very much.