It could use pacing. It started out very slow, but that's not always a bad thing, but it picks up very fast once you get the auto hammer and starts go go real fast. I got bored before 100%, but from not seeing any thing past max out the last two upgrades, one doesn't do anything and the other is just a few more 8% speed boosts.
It very much needs an auto sell. You can left click and press s, which is what I did, but... it's an incremental game where the goal is to automate to the point where you aren't playing it any more. I love these games. Where's the auto sell?