What I'm hoping for the most out of Prime 4, is for Samus to control exceptionally well, both in terms of her mobility, and combat prowess. I think Dread has the best controls and feel of any game in the series, so if Retro could somehow convey Samus's power and speed in the way MercurySteam did (but obviously in a manner more suited to the first-person adventures that the Prime games are), I'd be really stoked about that. The standard for first-person controls has shifted a bit since Corruption, with games like Titanfall 2, Doom Eternal, Halo Infinite, etc. reemphasizing the joy of deftly navigating a space using dashing, sliding, wall running, grapple hooking, and so on. Basically, things that just so happen to be perfectly suited to Samus's character. She's already capable of all of the above (praise Dread for taking the initiative to expand on her movement!), with the exception of wall running... and if they ever give her the ability to do that, I'll flip my lid, in the best way possible. It's just a matter of interpreting the game feel we love in the 2D games, but for the 3D / first-person space.