I got my yummy cake in 280s – pretty difficult.
Really creative idea! Here is my feedback: The platforming controls are very twitchy. You really need to be precise with movements. Maybe adding a bit more smoothness to changes in speed (especially when dashing and in speed mode)
I see that you tried to make the current powerup visible on the character, which is GREAT – but it only shows up while that power is active (so while falling with gravity, while dashing, when you double jump). I think maybe an indicator thats always there by the character that shows what your current power is would be nice.
Overall though, it is an interesting use of the theme and a nice complete game. Great job!