I liked this! Found a couple of bugs:
- Sometimes the item shop doesn't show the full list of available items unless I purchase a consumable. Then it resets back to normal. my.mixtape.moe/dhxecu.jpg
- Also this happened for some reason: my.mixtape.moe/gbuxyi.jpg
Design-wise, I really liked the eye monsters and the overall creepiness. I feel like the Metroids should do more than just float there. I tried leading one up to the surface but nothing happened. I also couldn't find the 001 item or the third !@#$. I assume some features aren't implemented yet.
I'd suggest finding some way to encourage the player to explore horizontally. It's so much safer to just dig a hole straight down. Being able to fly means you don't have to cleverly spelunk to the bottom like in Terraria, so once you get the hang of the game, it's a very simple loop of dig -> come up for air -> repeat.