This game seems nice to play with friends. Also luckily parsec works !
I tried rewinding couple times with no effect I dont know how it was supposed to look or work but at least you had it in there. For a jam game this was a solid attempt though id like it more if you made the enemy AI instead of waiting for a person to join with parsec or having someone come over to play it. Id say thats the only main issue, another issue is projectile speed. it seemed too slow so if i were you id definitely look into making it faster.
Overall pretty fun project and when playing with someone you loose track of time. Keep me updated on the future of the project and thanks for making this !
If you have some spare time and are available give my game a go as well and leave some feedback for it as id love to hear many different opinions for future development. Thank you and cheers !