Ah, yes. If you escape on Normal difficulty you will unlock Fever Night Mode, I could do a bit more to make that a little more clear. (I made tool tips that explain it, but maybe it needs more)
Boosters, they have a cooldown, I could probably do to add something visual so players will know how long they have until the next booster. I once had a bug with unlimited cooldown free boosters and... boosted endlessly until I reached the limit.
Thanks for the Feedback!