In the Powder Toy
It's worth mentioning that although "intentional lag inducing or crashing saves are prohibited," searching "lagger" and "crasher" both give multiple pages of relevant results. Although it would be possible to report the most egregious examples, this seems like something that could be automatically detected relatively easily. A save could be categorized as suspicious if the first 10 frames takes more than 5 seconds on a specific computer, for example.
This wouldn't completely protect against lag inducing saves, of course, but it would at least set a standard and discourage intentional "laggers."
tpt checks for reactions every frame i think so thats why, also i have 10 fps or less in most saves so yeah :shrug:
Try the parallel toy