Quickly

Whoa! In addition to the placement tips I just shared, prioritizing card upgrades at the 'Forge' right now is the most efficient strategy. Break the low-level rocks in order and focus on unlocking the mine passages first. If you use your time-saving potions wisely, you should be able to progress even faster, right?

Watch all the ads you can without skipping, and if you want to speed things up even more, buy the time-skip items in the shop with green diamonds. Anything beyond that would probably require real money.