Lego trains are a whole sub-hobby with their own enthusiasts, not including me. This little set probably does not belong in that class – maybe it’s a scale of some Lego train track, more likely not. I think it’s probably just a cute creator set in a different transport theme.
As is often the case in these Creator theme sets, there’s three models in the instructions (that cannot be built simultaneously). As well as the main engine, there’s some sort of repair/inspection engine and a carriage.
My current enthusiasm for small Creator vehicles is growing my collection of the 1 x 2 transparent brick without a centre tube. An ordinary 1×2 brick (3004) has a tube underneath it that engages between the studs of the surface it’s attached to. That would look odd when the brick is being used as a windscreen (in a transparent colour – clear or black usually) so these bricks “1×2 brick without bottom tube” 3065 omit the tube.
Another thing perhaps worthy of note is the use of Technic bricks and axles to join different sections of the model. This is a technique I haven’t seen before. In a larger model it would cause a problem for playability, but it seems fine in this little train. Even so, it was an odd decision, usually the ‘locking’ of parts with overlapping studded attachments is a hallmark of official TLG set design.