The Basics

Shoot a numbered tile into one of 5 lanes. Adjacent tiles with the same number will merge to a higher numbered tile. Higher merges give more points, get most points before a lane is full which causes the game to be over.

Difficulty

The difficulty is that as you unlock higher numbered tiles, it will be harder to make merges.

Variation

Only variation is the order in which you get the tiles, for the rest it is just playing the same game.

Visually

Simple, but functional.

Free vs Paid

There are advertisements but not too obtrusive.

Is It Any Good?

I give Number Tiles 7 out of 10 stars. Good, but I have seen it before.