Stupid but fun. For those who haven't figured it out yet, the game seems to use some rubber-banding where your opponent goes faster the faster you're tapping space, so you don't actually NEED to mash space super-fast, and doing so may be self-defeating if you can't keep up your very fastest pace indefinitely. Instead it's better to pace yourself, and keep yourself just about even with your opponent with only moderately rapid spacebar tapping. Although also for those who haven't noticed yet, if you lose, you get a different ending depending on what stage of "booster" you've achieved when you lose.
(and to the developer: The play again button from the "wrong kind of fast" ending doesn't seem to work)