Oh I know. I have a linux laptop that I use for gaming. I'm just going to a party where we plan to play gmod and some of the others don't have laptops so I thought I'd see if my Mac would be suitable. It wasn't.
Just tried Steam for Mac the other day, and there is a very good reason why it's so low. Modern macs don't even let you play games made for Mac!! Since 32-bit support was dropped, you pretty much can't play any Source games like HL2 or Gmod.
I'm on android, so it is possible for there to be a difference here, but on iOS every browser uses safari for its webview, so there is absolutely no difference if you use Firefox or safari or chrome.
Starbound. I've played the crap out of it. I still haven't finished it tho...