i managed to eventually buy everything by the end of the game. i admit i never figured out what the difference between the first two pickaxes are, they seem to behave identically to me. (i also never really figured out how the mining actually works... sometimes breaking a rock seems to drop a million orbs while sometimes it drops 0). my main strategy was:

1. break all the rocks with one and two slashes on them, as they (usually?) broke in one hit and seemed to nonetheless drop a million orbs most of the time

2. once i had the horizontal and dynamite things, i would use them, then break all the rocks that looked like they could break in one hit

i eventually started also trying to hit the red rocks as i noticed one of the times i broke one it seemed to blow up which resulted in a bunch of orbs. but then sometimes they would do nothing when they were destroyed, so i don't know what the deal was. i never figured out any special effects the blue rocks had.

it seems like the horizontal mining tool and the dynamite both are slightly glitchy. usually i can't get them to activate really "on purpose," instead i just spam click while moving my mouse around and eventually they sometimes work. my best guess is they have to be, like, perfectly aligned to the grid to work?

i eventually unlocked the art, which is nice, although there doesn't seem to be a way to close it.

anyway, that's basically a description of how my playthrough went. hopefully something there is useful. here's what i personally liked about the game:

- destroying the blocks is satisfying even though there isn't a sound effect. i think the vfx work is pretty good! same thing with the way the blocks spawn in each time.

- i like how the gameplay evolves over time as you unlock the new tools. it is always, at least for me, a game of trying to efficiently hunt down all the easily breakable blocks on the screen, but the upgrades make it so you're looking for both cracked blocks and the 1/2 slash blocks.

- i like the art!

A unique variant on a clicker! Its mechanics are communicated just well enough to leave “figuring out an optimal approach” as part of the game. It would have benefitted from some amount of sound, and it needs a faster on-ramp to the first upgrade, but there’s a core of something here.

Hey! Just wanted to give you a heads up, on my machine when I download the zip I get the error 

"Error: Couldn't load project data at path ".".  Is the .pck file missing? If you've renamed the executable, the associated .pck file should also be renamed to match the executable's name (without the extension)."

There's no .pck in the zip file, so I think that may not have been included in the final version you uploaded.