I saw you wanted some playtesting so here's my 2 cents: Stupid enough but it took me some time to launch the game as I didn't get why the start option was greyed out. Right clicking seemed to have an effect but I didn't try pressing down then "enter" right away. Then the first thing you see after the menu is an empty papyrus of rare crystals and the sign "Back" is misaligned. So launching the game puts you into an inventory then back to the map then you can start.
I'm not too fond of the box in the sky that are platforms. I mean there are efforts put into the overall design but it seems a bit off. Maybe because I don't know why I'm a teenager with a wooden nailed club for a pickaxe.
I wouldn't played it for much more because I'm not a fan of exploding gas, there were no ennemies and I don't know what is the gem's use. But as the main big no: please, I don't know when I'm gonna fall and respawn or hit a new ground level and it's annoying because that's the kind of thing we know would repel a player since the first Sonic the hedgehog.
I hope you'll find something cool to do with those crystals/gems, it's kinda fun to make them explode and collect them even if it can be frustrating when one is stuck on the path of the gas.