Hello melbodev!
I saw your cart on the PICO-8 BBS, and had to give the demo a shot. I hope you won't mind if I leave a review.
'Marble platformer' is a neat genre. Although I've played other jumping marble games before, I felt that your execution was unique. Having one small marble on a large, condensed level, where you have to explore to find all the collectibles that actually progress towards the goal.
I really enjoyed the fact that I needed to explore the world by rolling and jumping. However, there were a few things that hindered this.
The timer was daunting, and the fact that I needed to collect what felt like more than enough shards frustrated my attempts to progress.
The experience I want to reap from a marble game is that feeling of tricky momentum which anxiously builds up as I leap across gaps and balance thin beams.
How this might come into play is by adding in a few more levels where you can sprint across the tricky, twisting terrain... or slippery skinny sections, or set-in marble-run tracks where the player is desperately out of control. If things go off the rails, that's good... and if I can chaotically learn Tony Hawk tricks while twisting along distant tracks, that's even better.
I would like to come leave a really long review, so if you fix these things, let me know!
Best regards,
Artough