this is quite a nice start, there's a lot that i like in here for a first level. i think it could benefit for a little bit more distance vs height, and if each section was spiced up a little to make it something more than generic squares it'd be a neat little level.
to do that, i'd look into more textures. i only counted a total of 5 textures used (not counting objects), which isn't very vibrant. in the cave, for example, you could use the darker gfzrock2 instead of keeping with gfzrock all the way through. another thing you can do to add vibrance is add some varied geometry. for example, right when the player spawns there's a neat little ring box that's a little bit higher than ground level. this is exactly what i mean, small geometry up against the wall makes it more interesting than just staring at brown tile walls all the time.
to be honest, i quite like the flow in this level. it seems you went for a zigzag sort of thing, and it works quite well. sure it's a basic level, but i can still pick up how you crafted it to keep the player moving and turning, giving a constant sense of forward motion. the only nitpicks i have with it are that sometimes, this flow is forced to stop; specifically at the red spring and the super tight corners near the end. the red spring is right up against the wall, meaning the player simply has to go forward, let the spring play what is essentially a cutscene of the player gaining height, and then slowly start going forward again. not all that exciting, but with more varied geometry making getting to the spring something the player has to work a little for would help a lot. as for the tight corners, i usually suggest avoiding corners like that at all but i think it works given the zigzag nature of your level. instead, if i can make a recommendation, taking inspiration from gfz1 and turning that into a sort-of tunnel like how gfz1 does it to connect its two parts together would turn that into a neat little setpiece. without going too deep into it, i think the reason it feels like flow is stopped here is, on top of having to slow down to avoid hitting walls, because it's super claustrophobic and the theming is identical to the rest of the level. when you get here, the theming tells you that it's gonna be similar to how open your level has been at this point, so when it's not i guess it feels like the player was deceived? if it looked different, however, the player would recognize that it's not familiar stuff and suddenly unfamiliar flow feels natural, if that makes sense.
and now small nitpicks i couldn't find anywhere to put:
- the player spawns looking at the wall, instead of the way forward. remember that the angle set for player spawn objects defines at what angle they spawn
- the trees are too close to the wall which makes the leaves clip into it when looked at from most angles
- the checkpoint respawns the player looking at the wall, instead of looking outside the little nook
- the brightness is maxed out. usually, you want overworld/daylight brightness at 240 instead of 255 because that helps with depth perception
i won't talk about gfz2 at all since it's very incomplete, and at the current version it's practically just gfz2 if you had dust in your memory card
