Being the music guy on our team, I'm not an expert on these kinds of games. Keep that in mind for my review. Overall this was a nice story, beautiful art and fun to play! A few bugs left, some that were a little frustrating. 

Gameplay:
Everything functions as intended, I did find difficulty to be a little inconsistent. I found the bears to be far far more difficult than anything else in the game. One bear in particular (the fourth bear that you see, last that requires stealth, just before the chase scene) could see thorough the rocky outcrop/tower so I wound up having to treat it as a chaser rather than a stealth enemy.

This section had me wishing there was a way to get back to the save point faster, I found myself mashing through the dialogue every time I died.

Compared to those darned bears, I found everything else a lot easier. I breezed through the spiders first time. I thought the section with darkness and relying on the thought mechanic was a lot of fun!

There was also a small bug where you could walk up the spiderwebs to the top of the cave wall.

I did also experience looping in the final cutscene.

Story:
I had a lot of fun with the story, I found the characters very cute, I was definitely very invested and was eager to see how it finished.

Presentation:

This game looked beautiful. The art style was great. I had fun with the little notes on the map and the comments on the items in the backpack. As ghostinthegame mentioned, the UI as really good too. You really went above and beyond here!

Creativity:

There were some really cool mechanics here, with new mechanics being added pretty regularly it kept me engaged. The thought mechanic as a hint tool in general and its specific use in the darkness stage come to mind as things that jumped out for me. This game has a lot of personality that jumps out at you.

I also really loved some of the noisy music tracks. The music that played during the flooding in particular stuck with me.

Horror:
Not a lot of this particularly scared me, and I'm not too hard to scare. I did jump when I heard a sound in my house while playing the spider level. Saying this, there was a great sense of dread and macabre throughout. I got a sense of the setting, but nothing was making my heart race.

Theme: 

This very clearly fits the theme. As for bonuses, there were plenty of mazes, there was a cave in, there wasn't a player choice regarding preparation. 

Conclusion:

An hour and a half of my time well spent, hoping to see more from you in the future!

This was a solidly high-effort entry! Definitely noticed this was a collaboration between four people who each did their own maps.

There was a map that had me check how the map was structured and discovered it had around 300 events while it was running a parallel event that constantly saves player position into your variables. If you're not aware, any time a variable or switch is changed, it calls the map to run a check to every event to update its page, which in the end that map ran at around 2 FPS on my machine.

The version I played also had its ending cutscene stuck in an endless loop and the tone feels more like a drama/thriller than a horror. Otherwise this is a game with fairly challenging gameplay

Gameplay:

Gameplay was pretty serviceable, used the basic controls and a couple chases, a couple fetch quests. I enjoyed the concept behind the bear puzzle where you had to hide from them, but some of it seemed a little buggy at times? It wasn't always clear when I was visible to the bears or not, and especially the third one or maybe the chase bear? It would sometimes run all the way down to me when the dialogue popped up, and so I had to go through it a few times before I was able to make it through the level.

There also seemed to be some mechanic related to darkness, or maybe stress? I think it was connected to the blue bars on the UI next to the WiFi bars, but I was never able to figure out quite what it was and what it did. Which normally wouldn't be an issue, except that sometimes I would mysteriously die in the game, for seemingly no reason? In the bears section it seemed, straightforwardly, to be as a result of being in the dark for too long- ok, makes sense. But in later scenes, like in the spider section I wasn't really sure what it did or how to control it. Was it just there to put a timer on certain actions or sections? It was a little strange to me that it hadn't been explained, or maybe I had missed the explanation, because most of the other mechanics of the game were very well (and very cleverly!) explained.

Story:

In lighter scenes the writing was pretty cute, and as the game went on I think it did a good job of helping the player to understand Plane's mindset and motivations. I also like how the game subtly reinforces small things, like how it's mentioned offhandedly that Plane likes to work out but not cave-dive, whereas it's obvious that his friend cave dives a lot- and this is reinforced in small ways, the granola bar in Plane's backpack and Plane's friend's nonchalance at being trapped at the bottom of a cave.

Presentation:

The presentation was very good! The art was very cute, and every seemed to match itself from the tilesets to the characters to the UI. The UI itself was also very nice, and implemented some custom touches to really make the game feel unique as far as RPGMaker games go. My favorite was near the start when the game was walking you through some tutorials, I liked how they naturally included some of the keys used to bring up certain menus or actions within the explanation of such. Very cute, and clever.

Creativity:

I liked some of the newer aspects of the UI, some changes to menus and certain basic actions you could take (a button to talk to your friend! A button to open a map!). I also enjoyed the character designs, some of the puzzles had interesting ideas behind them even if their execution felt a little strange.

Horror:

So far the horror in this game is less "spoopy monsters trying to eat you" and more about the stresses of realistic cave diving. I mean, besides the glowing mushrooms (which may actually exist??) most of the things Plane encounters in the game are fairly realistic. It's not that it can't work... I'm just not sure that it's used in a "horror" way here, or at least if it is then it's subtle.

I think there was also perhaps some sort of sanity system in play, but I don't know if it was explained anywhere and it also felt unpredictable? I liked the static that would sometimes appear when the "sanity" dropped, thought it would show up mostly in light-hearted dialogue which kind of muddled the mood... this and other aspects were clearly borrowed from other horror rpgs (the chase sequence, hiding from enemies, even the lamp and limited light) but again, here they either don't feel too scary, feel buggy, feel unnecessary or feel included only for flavor.

I also think the writing itself did a good job of showcasing Plane's rising stress, his being fearful in an environment he's not familiar with. I do feel for the guy. I just don't feel fearful with him, if that makes sense. The lamp is far too bright, the lit area too large to ever make you feel like you don't know what's around the corner. The ambience is fitting, but also emotionally neutral for the most part. There aren't really "scary" sounds as far as this game goes.

In short, this doesn't really feel super like a scary game.

It does take place in a cave, and our player character does go deeper underground! I'll give props to the team, they certainly employ enough maze-like structures that that bonus challenge isn't really in question. As for Cave-In or Prepare for the Descent... I think Cave-in was meant to be the flood you run into, so props for that as it was a pretty creative (and yet very fitting!) way to include that challenge. I'm not sure that Prepare is included, though at this point I'm starting to wonder if I fully understand that Bonus Challenge myself, hahaha.

-Final Thoughts-

If I only talk up the spider portion, it's because I couldn't get past them, heh heh. The seemed like a little too many rules about them- the mushrooms stop the poison, the mushrooms stop the spiders from moving, not to mention the blue bars "drain" when touching the spiders, but sometimes it drains on it's own too? As well, sometimes the spiders would freeze when I stepped on a mushroom- other times they wouldn't. Sometimes I would gain back blue bars when standing still, in an area where there (at least seemed to be) no spiders. Other times I wouldn't, or even it would drain on it's own.

It's too bad, because I was liking the story and thought the novel UI and graphics were very cute. I'll keep trying to finish, but it's turned into quite a frustrating game.