Positive & Negative Feedback Loops

In a positive feedback loop, aka the converter, the output is fed into the input to reinforce the output. The more money you collect, the better weapons you can get, so you can kill more monsters and make more money. This process can be a mindless grind or some sort of a puzzle. Making this process fun.

A negative loop, aka a drain, is removing resources from the economy. Units die, resources rot etc... Drains can become an element of frustration: like when you die and loose all progress.