Alright, here goes.
While going through the starting tutorial room, I read the sign saying that you can press jump and crouch at the same time for the long jump. But I still had to hold crouch for a very short moment to "activate" the long jump (0.3 seconds or so). This may not seem like a big deal, and I may only feel that this is strange since I was trying to long jump like in Half Life (where it's instant). But his resulted in me holding crouch for even longer to make sure I wouldn't mess up, and having to slow myself down annoyed me. I think it would be better to make the delay as small as possible, or even take it out completely. But maybe there is another reason for the mini-delay?
Concerning the weapon behaviour I noticed that vaulting over a ledge cancels all other actions/animations, such as reloading and charging a shot. This was strange to me because normally you're not allowed to switch away from the blaster without firing the shot you just charged, or switch away from the over-under shotgun before automatically reloading after firing both shells. It's useful for saving blaster ammo, but it seems unintended.
Now for the level progression. After exploring Windmill Acres i had 5 out of 6 souls, but couldn't get into the caco tower. Searching around for a way in did me no good, so i begrudgingly left the level and found out that I simply had to enter it again to progress, through the last mission option. This was unintuitive to me since I was able to find the first 5 souls without starting another mission. But I understand that it was probably designed like this because the last mission repopulates the level with cacos to fight before getting to the tower.
Something similar happened in Serenity Shrine. I explored the whole level, but still had to re-enter through the specific mission options in order for Wantopus to spawn the soul and open the gate. I get that this is probably a good way to give players some pointers for where to go. But it makes me feel like exploring the level on my own is pointless since I'm forced to let the game lead me to these secrets again anyway before I can collect them. Maybe there could be some sort of way to include Wantopus leading the way in the "first" mission? Or better yet, let the player collect the secrets on their own and have Wantopus as a backup plan if they don't find it by themselves?
Trying to explain these thoughts in written form is probably not ideal, but I hope they are understandable nonetheless. I look forward to your opinion on them, so until then.