This game is like if Dead Space had a baby with OFF, and I find that to be extremely appealing. I can tell there's a ton of love in this project- charming artwork, great soundtrack, and lots of cool mechanics to boot. Climbing was cool (even if it didn't change much gameplay wise) and I loved all the unique sprites the enemies had. The lines at the end of the third area were super awesome.
I couldn't help but find myself begging and praying for more party members as I kept playing the game. Not necessarily because it was too hard- but more so just to have new characters to experience the world with, and have banter with our protagonist.
The setting is easily this game's strongest aspect. While very transformative from a general 'underground' theme, it's very striking and I enjoyed it greatly.
My only criticisms- combat became a bit simple and repetitive after a while (which is better than it being broken), and I got stuck on the second code as well.
Fantastic work!