Paper Train Lite is a game that offers a mix of strategy and time management. You have to control the traffic of trains so that they don't collide with each other. You do this by stopping and starting trains and by re-routing them around the map. During the first levels, you only have to control two train tracks, but as you progress, there will be more tracks and trains on the map at the same time. You are given points for each train that leaves the map unharmed and you are deducted points every time you stop or start a train, or re-route one.
There are quite a few different levels. The first ones are easy, as long as you are patient enough to let trains pass and take your time to let those ones that are stopped go. One of the other difficulties that arise as you progress through the game is that trains are of different sizes and they may move at different speeds. When the rails cross each other, the game also becomes quite harder.
All in all, this is an excellent casual game, and it has many levels. If you are looking for more of a challenge, the paid version comes with more obstacles and more levels.