Really cool concept, but the stat boosts from xp don't feel very useful. They should either be linear or exponentially higher so the lower levels feel less impactful and higher levels feel way more impactful. Anything above x2 is almost completely useless atm. It cuts your time in half and then just feels like a grind for a 5s difference on the long tasks.
The dig in Laurion also feels too grindy. Would much prefer fewer, but more interesting layers. The last 2 are great with resource management. The others just felt like I had to redo the tedious start just to chip away at them for 3-4 loops. If I could skip the entirety intro of leaving the original station it would be much better. Or if there was more new things to do in the original station, such as longer tasks that I would need to grind up some levels to do. This once again goes back to the higher levels on skills not being useful. Once you hit loop level 25, it takes incredibly long to go beyond for basically no reward as you only need a couple of tasks to hit that important x2 multiplier.
Also a feature to set which resource will have priority on being consumed would be a nice addition.
These are all the things I think can be improved. Otherwise the game is great.