The gameplay is very simple on paper but more complicated in practice. You will be creating train tracks in 3D (you can lift them off the ground) so that several trains can pass one another and arrive to their destinations without crashing. Luckily, you can undo any change and go back to the point of a level at which you made a mistake.
Cube Trains has more than 50 different levels and, even better, a comprehensive level editor that allows us to create our own levels: you can choose the type of terrain, the pieces you'll be able to use, the number of trains, etc.
Cube Trains is a good puzzle game that will keep you busy for hours, since it's considerably difficult but very entertaining. Additionally, you can play the levels in any order you want. So, if you get stuck on one, you can always jump to any of the other ones and keep playing.