I played the game for a lot longer then I expected, and just want to share a moment in this game that actually made me go "oh crap" and really encourage me to keep playing.
As I was digging I noticed the Down arrows and "Keep Digging" signs. And I thought those were nice. They helped me realize that I still had ways to go. However... the moment I saw the "Save us!" sign I was suddenly REALLY curious and determined to beat the game.
When I got to the room with the lab and the bloodstains everywhere, I REALLY REALLY wanted to beat the game and figure out the mystery. Unfortunately I think the game doesn't really build too much further upon it (maybe for time reasons). But the curiosity I had made me keep playing and digging. I think things like that are really powerful and shows how useful of a tool mystery can be. I feel like you started with something cool there and gave me a moment I didn't see in any other jam game so far this time around.
I did appreciate the Boss fight at the bottom to mix it up. It was a nice thing that was different from the rest of the gameplay. I feel like it was a bit too memey maybe? And an ending dialogue would actually add so much.
Uhh... random other comments. I feel like most of these fall under the "Probably just ran out of time" style of critique, which isn't too helpful, but I thought I would list it out anyways.
- Gems and Ores could use a name. It helps a bit with immersion.
-The Artifacts you dig up could also be made more immersive if they had a name you could see somewhere. I thought finding Artifacts were really cool, and here is where just a little bit of flavor text and a name can really help with the whole sense of mystery.
- Some way to tell the value of Ores in the inventory screen could be useful.
- Jetpack ramps up in speed very quickly once you upgrade it, making it very hard to control.
- Taking damage when falling could use some kind of indicator. I actually didn't realize how low my health was getting due to this.
- One actual point. I THINK the water you run into is an indicator for when you run out of time. I think this ended up confusing some people who thought that they dug too deep or something. If this is the case, I think a simple transition like a fade to black with some text could have avoided this problem.
- Sprite art is nice! I'm guess you drew most of it for this jam.