Brax envs difficulty levels

[seyeint]

Cheers, I'm currently running my personalized evolutionary algorithms through EVOX and I'm also testing them in different Brax envs, not only in numerical optimization testbeds.

1. I was only checking swimmer and halfcheetah but I'm wondering what are some of the hardest environments to achieve good fitness (like top 2 or top 3);

2. I'm currently using very simple MLPs and I just switch shapes depending on the obs and action dims of each environment but I'm not really sure if there's like a general architecture where people benchmark their stuff? img below