I won't lie, this is my go to mod for Coop DX.
The mod is really, really well made, with lots of talent behind it. The movesets themselves are really fun to use and the skill ceiling is above the sky for speedrunners, and the models look dead on official, like I can legit see this being the Super Mario 64 sequel that got canned on the 64DD. Even the small details, like WaPeach having stars over her head when dizzy or Rosalina's galaxy spin. I bet they were a pain to code in.
I always really liked mods that are subtle additions to the game. I feel like some, while amazing and excellent in their own right, feel like overkill. Sonic, for example, feels like the controls of the classic games and Adventure just ported smoothly into the game. None of these characters feel like they're overpowered, or even underpowered, besides maybe Waluigi, but that's really more of a nitpick than anything. I adore the option of the Slow Down Boots because it goes well with game modes like MarioHunt, Arena, etc. I personally don't use it, but it's nice to have for people that possibly think Sonic is a bit much. A hot take, at least for this mod, is that I DO legit like the voice acting here. I always would prefer the sound coming from official material, but the voices fit well here, and even if it's a tad uncanny to hear Birdo speak, the performance is really well done, so the uncanny thing wears off immediately. One small complaint really is the alts. While good choices are picked for some of them, the other half feel like filler to me. I adore the references for long time fans in some of them, but a good example is Mario's alts. The last two feel detached from the other two, however, I think if the alts are bumped up to like 10 or 15, it would feel less jarring. It doesn't impact my experience, which is why it's still a 5/5, but just something I wanted to bring up.
I am eagerly waiting for more, what this mod has to offer. Great stuff!