Really peak game tbh. I'm suprised how much y'all managed to make for this game lol. More importantly, I'm surprised just how high the quality of this game is all things considered.
The presentation is genuinely exquisite. Each section had a cool look to it along with a unique feel with the music and colour pallete. Along with the pixelart being visually stunning, I loved how readable the game remained from beginning to end. There were one or two sections where the spikey things on the walls blended a little too much into the environment, but everything else was clear at first glance.
The map was also really well designed. The pace at which I unlocked new powers was fun and there was a solid variety to the enemies and bullet patterns that get thrown at you. Same for the obstacles in the world that block you. The fish and the computer terminals with lore were also cool. The character that you meet that increases the water level also reminds me of the main character from the other game that y'all made in terms of it's looks ( Ballet of steel )
All that said though, I wasn't entirely a fan of the actual gameplay at first. The player character moves too slow in general. I realise that you guys probably did this with the aim to get a player used to the grapple hook and to have them learn what can be grappled to and what can't. However, the grapple hook itself was kinda finnicky to use. I think it wasn't as clear as it could've been whether you could grapple or not sometimes. It would probably help if the mouse icon turned red or had a different icon or something over surfaces that you couldn't grapple to since the sound effect that seems to play isn't too audible.
Once I started to get more abilities though and the drone could actually move faster and had a longer grapple range, movement felt far more fun. I also love how cave story's weapon upgrade system was implemented here. Definitely had me try to dodge as much as I could.
Criticisms aside, this is still a phenomenal jam game. Kudos to the both of you