What good difficulty tuning looks like

A game can be hard without being unfair, and the gap between the two is where a lot of mobile strategy titles stumble. Fair difficulty teaches you something every time you lose.

The clearest sign of good tuning is being able to point at your mistake. In Lantern Line Defence, when a wave breaks through, I can usually see exactly which tower I skimped on. That's the game working.

Bad difficulty hides the numbers or spikes suddenly with no warning. If a level suddenly triples in strength with no chance to adapt, that's not challenge, it's a wall designed to frustrate.

Look for games that ramp gradually and let you retry quickly. The fast retry loop is underrated. It keeps the sting of failure small enough that you want to try again immediately.