I really enjoyed playing this! It's really satisfying to build up momentum and Tarzan-swing up and down between the evil red blocks. I don't really see the connection to the theme (I can sort of see "reverse" but not "rewind"), but otherwise this is a super fun and interesting game! Awesome job making this polished of a game in only a week!
P.S. If you intend on expanding this at all, I noticed a small bug where red blocks would spawn underneath the black ones and be pretty much invisible, but they still kill you. It only happened once in five or six rounds, but I just thought I'd let you know in case you weren't aware :)