I played on "hover" mode.
For some reason, it felt like the same room over and over again. Buying upgrades didn't seem to make much difference, since they almost never trigger. Even though the blocks look different and contained different ore, I couldn't detect any mechanical difference, so breaking the blocks all felt the same. Waiting until room 5 or room 473 for an upgrade just feels like torture, and it probably means each run plays the same, since you'll take the upgrades in exactly the same order.
I've played other clickers where the goal is to mine an area by clicking all the tiles. Maybe check out Arcane Earth, which has a lot of ideas I think you could borrow to improve your game. Most significantly:
- you can buy the upgrades whenever you can afford them
- there are a variety of upgrade paths, including auto-miners that can clear a screen relatively quickly
- the layers are fairly large, with lots of blocks
- sometimes just mining a tile triggers a special effect (magical weather) or you discover treasure (trinkets, rare ores) these all have an immediate impact on gameplay or allow you to buy upgrades sooner.
If your game already has some of these features, you should let the player see them sooner. If I've been playing for several minutes/rooms and nothing's changed, I'll start to think I've seen everything the game has to offer, even if there are still hundreds of rooms to go.