I love a good mining game. I enjoyed just using my pickaxe honestly haha. However,you utilize the Rope Shot and Drill Shot well. I've personally never played a mining game with puzzle elements like this, where you have to be more intentional with how you use your tools. The O2 mechanic elevates the puzzles, adding a sense of urgency to each level.
While the Mega Drill is overpowered relative to your tools, the progression leading up to it made it feel less overpowered and more a product of ingenuity on the player's part. In that sense, and in the context of the mine, it lost the ridiculousness, you know what I mean?
Not that it matters too much honestly, I had fun with it and was always so relieved to unlock the Mega Drill!