Really fun for the parts that I managed to get to!
I made it to the big surprise on the left. I really like how each direction had a different difficulty level, sort of nudging the player to start with the right path.
My playtime was about 90 minutes, yet even with the upgrades, there wasn't enough noticeable boost to the distance I was able to cover to feel rewarding. Upgrades start to get very expensive for just a little boost. Would have been nicer if each upgrade gave more of an increase in O2, light, etc. Just too grindy right now - especially the rare drops.
Also the movement felt a little "sticky", trying to navigate through tight corridors - often hitting the corner of ledges and falling down - and frequently losing all momentum. Would feel better with less of a momentum lag when running from a stopped position. Or have more open corridors that are more forgiving.
All in all it was very fun