Solid game. A more dynamic tutorial would work better, gradually introducing mechanics instead of dumping all the info at the beginning. It becomes more interesting about halfway down once the darkness starts spreading. Good vibe, almost horror at times. I like the sonar mechanic, unfortunately I only picked it up once. At times the game seems too unfair with no way to avoid enemies. Controls could be improved, needing to hold left mouse for 10-20 minutes is not comfortable at all. Reached the 1000m.