There isn't a tower defense game that even comes close to the depth of the gemcraft series.

Superior goth Bloons TD - Schizophrenic wizard edition™

Gemcraft: Chasing Shadows looks deep at first. You see gem combinations, traps, amplifiers, spells, skill trees, equipment—tons of systems that suggest experimentation and strategy.

In reality, most of that depth is an illusion.

Very quickly the game collapses into one dominant strategy: mana economy. If you scale mana fast enough, enemies stop being a threat entirely. The loop becomes simple:

more enemies → more mana → faster scaling → summon more enemies → even more mana → exponential player scaling.

Eventually your gems become so strong that enemies die in one hit. From there, every level plays the same.

The actual gameplay ends up being this:
Hold B + Shift and spend the rest of the level going click-click-click-click-click to spawn enemies faster (to feed your mana engine)

That’s it. The “strategy” is basically how fast you can spam-click. The game doesn’t reward clever builds—it rewards obsessive clicking.

Ironically, the game even struggles with that. Once the screen fills up, performance drops and the input system starts queueing mouse clicks. So when you suddenly need to react (for example clicking the annoying tower-snatching enemy), the game ignores your action because it’s still processing the hundreds of clicks you already queued.

You sit there watching it happen, unable to react.

On the surface Gemcraft looks like a complex tower defense. Underneath, it’s mostly a repetitive click-fest built around a single solved strategy.