Collect All These Stones! (CATS)

Cozy Optimization Speedrun-based Idler Harvest resources, go deeper and deeper to the most rarest resources underground! Progress wisely, each new level is harder to dig but gives you more reward. Technology tree, different units and strategies are applied to reach better total time results! What will be your strategy to collect all that ore in the best time possible? Would you hire an army of human workers or run a swarm of collector drones? The choice is up to you!