People liked holding their breath.

Results are pretty good. My best score since I started doing game jams. I think what worked this time is I had an idea of an original concept pretty soon during the week-end. Also, I chose a minimalist style so I was able to iterate quickly on the idea and find a good presentation to deliver the concept.
Maybe it's a good flow for me to work with 1-bit pixel art to focus on the game mechanics.
After the game jam, I took into account the feedback and started to work on an other version with better graphics and better immersion. I tried a lot of style but finally managed to have something interesting with voxel art. Here's a comparison. There's still a lot to do.
Before:

After:

I also learnt that maybe I should consider making games with no pressure and focus on what I like. The game I made for LD57 is not a publishable game, there's no financial potential, it's just a game for a game jam. But working on it is a good hobby and maybe it is just enough.