I feel you. I had played the alpha and perhaps had a somewhat idealized memory. There were moments when I realized I had to duck my head before entering a tunnel and having to leave room to the side to clamber up into a pole that were exciting for me at the time, but on the whole, playing now, I don't disagree at all with your assessment.
The controls are much tighter when playing with a PS4 d-pad, or with the keyboard (the game absolutely does not understand analogue sticks, and all of the dev's testing was done on the keyboard), but they still feel kind of strange and muddy at times. The momentum doesn't always feel right, and the cat never feels quite nimble enough, even as I've got much better at the platforming. You get to have a feel for how long it's arms are when aiming for poles and overhead tunnels, which is nice, but I fear I may have overstated the virtues of the procedural movement in the face of it's sluggish control scheme.
The devs say they're looking at tuning the controls, but I of course have no idea what that will ultimately mean.
I can tell you some movement tricks beyond saying "no seriously don't use an analogue stick ever":
Hitting down when you hit the ground will bring the slugcat into a roll, conserving momentum.
Holding down while in the air will cause the slugcat to grab the first pole its arms can reach.
There is more stick to the wall cling/jump than in most games. You don't have to leap off instantly.
You can turn around in tunnels by holding jump and pressing the direction key you want to turn towards.
I have started to get used to the controls, at this point, and have begun to genuinely enjoy the game. Much more than the sense of crushing disappointment I had upon its release. But I can't say the doughy feeling ever goes away.