I play a lot of browser games since my Mac isn't very optimized for games. When I play I consistently get 30 - 50 frames per second, and I can't really play well. Are there any ways to boost fps with a certain browser, or with special commands? Thanks.
Some possible answers:
Try hardware acceleration if it's available.
Upgrade the RAM if the machine only has an integrated graphics card.
Use an eGPU if you're running macOS 10.13.4+ and have a Thunderbolt 3 port.
Use gfxCardStatus on a 2008-2012 dual-GPU MBP. This will only be useful if it's not already using the dedicated graphics card while running games in the browser.
Try using Windows via Bootcamp.
As aphid suggests in their answer, try lowering the resolution. This can be combined with other option(s) for maximum speed.
For flash based games, in particular
Flash games tend to be limited/bottlenecked to single-core cpu performance for their drawing, tend to have per-pixel calls. HTML video and flash on non-windows platforms often has no hardware accelleration support.
Apple devices tend to have very high resolution on their retina displays.
That means it (on a game-by-game basis) might also be very impactful to lower their resolution. (Play in a smaller than full-screen window or using zoom).