Yeah, I wasn't planning on making an end screen, just made it go back to the main menu, but I'll definitely add one if it confuses many people.
The heart collecting was meant to be like a gamemode type of thing where in some you just had to finish the level and then in others do some other stuff. But I'll probably make it so you have to collect all of the hearts cuz then you'd need to put effort to clear a level.
Thanks for your feedback! It really helps.