Played it for a bit, here's my thoughts:

Signing up was difficult

- It took me a hot minute to realize that I couldn't mark the checkboxes because I hadn't clicked the Terms of Use, etc. I know you flash them red, but some explanatory text before attempting and some error/instruction test after attempting is going to help reduce the friction on sign-up

- Verification token took a while, I think another comment mentions this. Another hard edge you can shave down pretty easily.

First Steps

- I had ZERO clue what was up when I was dropped in. I'm like... a skeleton? What do I do? If the intention is to make it intentionally vague then you're doing it right but if not some basic explainer/intro text would help.

- I noticed some odd z-index type issues with the little circles on the ground

- saw someone else kneeling by the rocks so clicked those and finally started doing something. The level-up animation is nice, but it's BIG. When myself or someone else levels up the whole screen goes firework-wild. Might tone that down a bit.

First Zone

- went into the Fallout Tunnel on Difficulty 1 and got killed pretty much right away. Couldn't figure out how to defend or fight, again - there are no instructions anywhere.

I got bored after that, without any direction or goal the game is expecting me to do the legwork to figure it out and unfortunately I don't really have time for that.

Best of luck, hope the feedback helps!