Glowish is a puzzle that has a Lights Out element. In Lights Out, the object is to light all the tiles. Tapping one button will toggle on/off that tile and its surrounding neighbors. In Glowish, the objective is the same, but the rules are different.
The Essential Rule: Tapping a green triangle will toggle all the triangles and all the other greens.
The first levels are pure easy: Just tap each element. Look at the first 2 images. There are 2 blue squares. The second blue square does nothing to add the complexity. The second image is a Venn diagram of the situation. Since none of the elements intersect: just tap each one.
1. Tapping the blue triangle lights up all the triangles and the blue square.
2. Tapping the orange square turns off the blue square, turns on the other squares and itself. And turns off the orange triangle.
You get the idea. I the actual solution was: tapping everything once.
There are 100 levels and I'm on level 61 or so.
I can't think of another puzzle concept that utilizes Venn Diagrams. Glowish is definitely unique & fun.