Why do the games run at super low FPS? Seems like 3 FPS or such. Mac Mojave, Firefox 67.0b3 64bit
In general: Repl.it infra is a multitenant container system and you might get unlucky sometimes and get a VM that's super crowded (reloading might work).
Btw, if you login we also give you more compute resources and things will run faster.
For the curious here is the cpu load avg thanks to the hackernews hug of death: https://imgur.com/a/QviYhG9
(Yellow line is a 100% saturation -- eek!)
More generally though we have millions of users that don't have the luxury of running a fancy local developer environment. Either they're on chromebooks or tablets or they don't have a computer altogether.