I'll start with the issues I had:
The camera and perspective suck. In coop player 2 dies when too far from player 1 and often hinders visibility. For some reason there is collision between players and we constantly kept inadvertendly jumping on each others head. This can also be exploited to skip sections, really unsure why it was implemented like that. When speedrunning levels, the camera has a speed-cap and usually gets left behind, lowering visibility.
There is a lot of jank, you sometimes grapple onto ennemie instead of grabbing them, you grab onto the other player's grapple, grapple onto thrown items, I ended up inside a wall somehow at one point, reviving in coop is annoying, most of decoritve flourishes have collision which sometimes harms platforming.
The final boss consitently bugged out and did his attack off center, sometimes off the arena.
Boss fights are kind of a slog especially when speedrunning. A quick restart for speedrunning would be appreciated, if i were to dodge checkpoints and respawn at the start it is quite fast, but as I was going for the timegoal + deathless i had to restart the level which would load it again. This would make the graphics bug out when done fast, particularly when I did it as I died.
I found the music in the second area grating.
P2 always despawns between levels.

As much as i have quite a few issues it was still a net positive experience. The game has a lot of charm. The movement is quite satisfying except for the double jump.
Ultimately i like the design of it. It felt more like a way to correct for the bad perspective with the trade-off of killing a bit of your momentum.

Once you accept you'll sometimes die unfairly to the bad perspective it isn't soo bad, coop helps for checkpoints. It works decently as a casual and coop game in spite of its issues. The game's fairly short, I beat all levels in coop in ~3 hours. The time goals on levels almost make them a second set of stages where all of the jank can be exploited (at least some exploiting is expected). It took around 2 hours to redo levels for missing goals. It didn't overstay its welcome. I got all achievements but there are still stricter time goals. This makes the 100% more accessible while also adding a bit of content still in there. Since the game is built for speed, i imagine it is quite good for actual speedrunning.

I give the game a 8.5. Although I thoroughly enjoyed my time with the game and approve of the design choices, the execution wasn't quite there. At full price the game is lacking a bit in content especially if you don't plan on engaging with the speed aspects. But hey i didn't plan on doing it either and I'd say you're missing out if you don't.