The new GFX repls currently experience high latency and frame skipping. As of now, someone can't accurately judge a game because of this. Even if the game is well optimized and can achieve playable frame-rates under normal conditions, the person playing it will experience quite a bit of lag. My internet (~ 80 Mbps) is capable of running GeForce now (a service that streams games to your computer) at 1080p with barely any latency, yet I still experience lag when running GFX repls. This means that the lag is mostly independent of one's internet connection. I've modified the example Pygame repl so that it prints the FPS to the console. It runs at a very steady 60 FPS but is laggy enough that it can be difficult to reach the top platform. Try it yourself here: https://repl.it/@joshwood/Pygame-Latency-Example
I'm really happy that Repl.it now supports more options for game GFX and I understand that it is still being worked on, but I don't think it would be fair to mark down people who utilize it simply because support for it isn't 100% complete yet (especially since it was advertised as a way to make your game for the game jam).
While I realize that may be against the spirit of the Repl.it, I think it would make sense for the judges to download any GFX repls and run them locally when evaluating the games. Having high latency can make a really great game not a lot of fun. And due to the game jam's massive prize, it's essential that each game is graded fairly.
I just want to emphasize that I don't mean to criticize Repl.it or the game jam by writing this. Repl.it is an amazing service and I think this game jam was a great idea. I just want the entries to be graded fairly.