Yeah, true, you can not. Given the fact I didn't have a ton of time, I focused on how to create a main mechanic: midi file is being translated to spawner of these emails. But I totally agree that it's more of a prototype than an actual game with levels and lose state.
Thanks! These emails are actually me hitting drums on the midi recording. Basically, Godot Midi plugin allows to listen to note on/off events, and the rest of it is just a matter of spawning something on the correct track with correct timing.
I tried to use ones from the music file first, and it even worked, but was insanely hard to play, needed to simplify.