I wanted to edit my description to explain the controls, but I get why that wouldn't be permitted. Just haven't heard a definitive answer yet.

I don't know about the submission page itself but you can edit the game page. The only thing you can't touch is the game files of course. For exemple, I edited my page to add a gameplay video, screenshots, gifs...

For the submission page itself I'm not sure.

Oh I meant the game page. Edited the title now! So nothing bad will happen if I edit my page, it seems?