Amazingly done, pressing the button really feel like doing something meaningful here rather than a chore. My only nitpicking suggestion is to allow starting the game with keyboard as well, which is as fast as setting the default selection to start and allowing options switching with navigational keys. Otherwise, the level of polishing is over the top, I really want to give more feedback but I don't know what more to add to this game. Very well done!
Do you mean starting from the title screen? You should be able to just press "Enter." You're right though - it doesn't say that outright anywhere. A little key icon would be a great addition for a post-jam update. Thanks for the tip! Glad to hear you enjoyed it. :)