Bitsy's CPU usage spikes, the game input response time plummets, and the Chrome browser GUI also slows to a crawl. Games are basically unplayable. This has been true for me for at least the last three Chrome version auto updates. I'm currently at 70.0.3538.102. I'm on Mac OSX 10.12.6.
I don't feel like this problem existed when Bitsy first launched.
I have this problem for many Bitsy games I try. Some example offenders: