Hey, good job on the design. I have some notes or questions.
In my opinion, you (and your team) might be too punishing in certain areas. For example in the first image, near the large windows, the floor is filled with spikes, yet it is an unneeded punishment, as falling already punishes the player. Why did you add that additional punishment? In Gretel Level 3, similarly, the spikes only offer an additional punishment. In Hero Level 3, I do not think the spikes are too punishing, as they are the punishment for falling and you restart in the access area. If I could summarize my comment is that spikes should be a challenge to overcome, not a nuisance.
Also, it seems you have the concept of platforms (places where you can jump from under it to the top of it, and perhaps in reverse as well). Why not introduce them in the spiral staircase? It would facilitate navigation and simplify travel.
I also noted a disconnected platform at the beginning of the level. Try to avoid unnecessary content that might guide the player to nowhere. Why would the player go up there? Is there an enemy below? Is there a coin on the platform? (The reward can be the narrator talking.)
Overall, I think you guys are on a good track for a great game! If you want more feedback on the levels reach out to me on Discord and we can chat.