Good potential
The game engine is pretty good and the scenarios can be interesting. But there is a lot of room for improvement. Adding ISO/SAE switch to the excavator controls would help. And making the controls proportional like real valves would allow for more precise operation of the excavator. Physics need to be improved. E.g. rocks jump out of the bucket violently on their own or all 10 wheels on the truck sliding around on dirt on hills with a heavy excavator on the trailer is very unrealistic. May I suggest other scenarios such as loading/unloading the excavator on the trailer?