"I lost and then won within the same run" - that's an obvious bug :D I'll fix it.
"Maybe the losing screen shouldn't come when the water is barely knee-high." - I think it's fine for the prototype but I'll keep that in mind if I decide to make this project into a full release :)
Thanks for playing and for the comment!
A fun bug, nonetheless ;)
I think losing the second the water shows up would feel a bit sudden, anyway. When the water is above their heads would probably be the best moment; that gives the player some extra time after the "it's too late moment", so they have a bit of extra time to put get a chance to complete it if they get a move on. And it's just more realistic.