Trailrunner is an interesting preview, mostly because it seems to be lifting a lot from the C64 conversion of Stun Runner, at least in the main sprite form anyway.
I wonder if Trailrunner was being developed in response to the poor C64 conversion, as the scrolling looks a lot smoother (even though nothing is really turning and there are no tunnels). But then the level does start with the title – “œThe Big Roundabout”, which is probably a bit of a joke.
Was it a serious game? Who knows? There is no coder credit to attach to the game just yet, so it could be a while until we find out.