Very nice game, also very fun to speedrun here is my best so far
I stopped the timer a bit late (the timer says 39.60 but the game ended at 39.23).
There is a lot of cool strats for the bosses in this game like the early stage 2 C# and the death at The Toxic Fan (this death might not be the fastest way but the fastest I've found, you might be able to just jump over the gas if you time it right)