Thanks for the lengthy review!

So to start, the 3D engine I made for this lags if too many objects are rendered on-screen at once. One of my workarounds was to have the world be fairly small and barren, but to incentivize the player to stay in one area. This is actually the reason the premise of the game is collecting firewood and bringing it back to a central point, as it keeps the player from wandering too far and realizing how small the world actually is.

Having everything (except the Dark Wizard) die in one hit was an intentional decision to maintain tension, especially since none of the enemies use ranged attacks. I like that the player never has to look at a HUD to see how much health they have left, and they can't get complacent just because they have a lot of health. Even though the game isn't especially scary I felt this design maintained a level of suspense that fit the tone.

The cursor getting stuck is something I've done just about everything I can for, but unfortunately Flash doesn't have any features for locking the mouse in place or even detecting movement (it can only detect position.) The first game uses shift lock and keyboard controls, this one added in a dead zone as well as buttons to instantly turn 90 and 180 degrees, as well as providing an AHK script. You may notice that other 3D Flash games (like ports of Quake and even Doom Triple Pack) have the exact same issue. requestPointerLock is an interesting idea, I'll see what the folks on Ruffle Discord have to say about it.

The end stats briefly display numbers for each category (time alive, kill count) but then tick down as the final score ticks up. I did this to make it look cool but I'll admit it is kind of annoying if you want to look at each number individually, and if you look away you might not even see that there was a number there to begin with.

Once you encounter an enemy, it's added to the Omnibus where you can see tips on how to defeat them. I did this intentionally (encounter enemy first, see explanation later) because I wanted fear of the unknown to be a big part of the game's atmosphere. As you discovered, this includes the Mimic which takes the shape of a tree, and the Stalker which is invulnerable to damage until it tries to attack you.

Regarding the ground movement, I believe perspective transform is only available for AS3 and this game was made in AS2. The animation is baked, though, so I probably could have exported a perspective transform animation as a different filetype and re-imported it into an AS2 project.