Like Wilt, a well made action-platformer, and a equally memorable soundtrack. Art wise I think the portraits can use a little polish, but maybe that's just Minotaur's style, so not a bit issue.
The most issues/suggestions I have are about the system/design:
1) I'd suggest a system which you can't make potions until you've learned the recipe, either by shuffling, like the wheel's combination or hard-code. The fact that you can get the potion as long as you have the ingredients hinders progress control. For example, it's possible to obtain anti-gravity before you saving the girl in Rogor , and simply ignore her when you go there. The game doesn't break as you can't enter the cave until you've saved her, but it glitches a bit when climbing the vines. (Touching the left of the upper vine teleports Zos back to the ground, while the right doesn't.) .
2) It feels tedious when you have to look up the recipe to make potions. Isn't picking what we want to make then simply press enter/space more intuitive?
3) The boss patterns needs some work. Prime example would be the mushroom, to pass, you just stand there and spam explosion. Having too little hp here is not something fortify health can't fix. The scorpion and the Dogas (pokémon) also provides virtually little or no challenge.
4) Some very little touches that would have been nice:
-More info instead of brief messages on some other easter eggs, since they didn't make it to medals, like Bullet(I still have no idea where he's from), Morax and Little Prince.
-More creative use of potions. (Speed have little use, reveal hidden and increase science are just potion fillers. Why can't I help the invincible man with reveal hidden?)
The game is fun to play, I started a new game just to find all health upgrades even though I beat it without all of them. (as there was no way to tell if you've found the one in a particular stage or not if you didn't keep track of it yourself.)
I'll list the locations here, as I've yet to see walkthroughs mention them:
Potal : Past the war zone, inside the house left to the entry of the factory, walk right past the wall.
Aeryl : Use fortify jump to reach the left side, pass the ice brick stairs, on the platform where you see a npc and an enemy to the lower right, jump to the left to land on a hidden platform, then again to land on the platform to the far left.
Rhisla : Use fortify jump in your own house.
Rogor : Past the first seed-spitting plant, use antigravity where you see 2 npc with a totem and fly toward the upper left.
Elaris : In the lab where you see 4 teleport gates in front of you, enter the left most one and use oxygenation on the poison cloud.
(It is actually possible to pass without
Meztla : At Rhisla's temple ruin with an npc, Inspect the left wall with reveal hidden to get the combination. Enter the temple to the left of Meztla, then use fortify jump to reach the higher platform.
Lynaii : Pass the first screen, use fortify jump to reach the upper house and get in..
Lastly, one question, I take it that the Xochthu was inspired by/a referene to Remina the Hell planet, correct?