I'm betting it's something to do with itch.io's web play. I only played the web version (not sure if a download was present) but I noticed the same kind of things starting to happen on my game both on my laptop and PC. Internet is in great shape so I'm definitely willing to say it's itch. Regardless, it didn't take away from gameplay! It was just a few stutters here and there and if I stopped moving for a second it seemed to catch up.