This is the type of game you could whip out on a dime on your phone and play to kill some time and have fun. Actually, the graphics remind me a lot of pixel-art mobile games, especially how they go in tandem with the gameplay! The start of a run is pretty slow but this mostly ends up working to the games benefit as once you get a few upgrades it really gets going. The main gameplay loop (at least, I how interpreted it) of strategizing how to min-max the most out of every session is addictive and the amount of time you get is just right. I thought the idea of having portals to end the run would've been a bad thing but it serves as a nice bow to tie up the runs once they start to run their course.
Also, this game would go HARD with some more juice & spicier sound design, like having special effects for mining ores. Wish I had more to say about the upgrades but they're all pretty good and the satisfaction of building up a powerful character is just a tried & true driving force to keep going! One nitpick is that I would've personally preferred if the bombs activated instantly, and you just had to level them up better.
Another thing is that I do wonder if the game would've benefited from having some kind of fail-state, but that would severely alter its design & direction. Like maybe you need to pay some sort of toll each round forcing you to focus on getting cash, or there's a limit on how many days you can take to beat the game, which you can extend by paying a lot. But that's purely my opinion and not a big critique by any means.
Overall this is a pretty relaxing & stress-free arcade game.