Interesting experiment. Feels a bit anti-climatic, though. As if the level was only the introduction to something bigger, like an episode of path-defined levels.
Classic style - except for the props of course. They look just a little bit out of place in a Quake environment, or least next to the idbase textures. Not a big problem really. I found that the doors, while being useful for making the small base appear larger, can be slightly confusing as it's unclear which ones open and which ones are simply detail. You could maybe change the textures of the doors that never open, or add some detail to suggest they are permenently locked, or at the very least centerprint triggers.
No problems with gameplay really, even though for a moment it felt like I broke it when picking the middle path. Got through it fine eventually. Quad path, too. Not sure why anyone would want to pick the slime maze, though. It's a bit awkward with all the pipes one gets stuck on. You can see how to get past them, but it sometimes feels unnecessarily finicky to actually do it. The path is doable, though you can just as easily fail. Not much fun really, and no real benefit apart from skipping combat (e.g. no reward weapon if you dive up in the hangar itself). Quad is permanent while the suit isn't?
Demos
On a technical note, the map exceeds the edicts and the models limit as QS reports on developer mode. I believe this is something that can be fixed with little effort. In the slime maze part, each pipe is an individual func_wall which is completely unnecessary. All of them can be grouped into a single entity per corridor. Even better yet, if you use ericw's compilers, you can just turn them into func_detail_wall and save a large number of models while getting the same result (phonged pipes).
Likewise, the blankets on the bunk beds, which are all individual func_illusionaries by the looks of it, can be grouped into two big func_illusionaries (one for each side of the room= left and right of the door), or simply func_detail_illusionary.
And if these two measures aren't enough, there's another big potential for saving models in the monster teleporter room. The trigger_teleports there can all be turned into point entities and they won't count as individual models.
Doing all of that will also lower the edicts count, though I'm not sure if it's enough to get it under 600 (in practice should be lower than, say, 570). But I can look into that if required.