The game exhibits 5 different difficulty levels. The difficulty level influences the sparsity of resources and the amount of black rock (non destructible) on the map. Other parameters like the speed of the train stay the same. While getting resources might be easier on higher difficulties, the focus shifts to planning ahead where to build tracks to avoid being locked-away from the train.
Kids mode has similar resource distribution as easy but forces the player to enable checkpoints which will be available at each station instead of only at the first station of each next biome.
Easy maps have a clear path on grass to the next station.
Medium maps have no obvious path to the next station anymore.
Hard maps are similar to medium maps but with more black (non-destructible) rocks.
Extreme maps have a high amount of black rock such that there is usually no path where players can walk next to the train at each track.