Hey, I've recently bought OTC and I'm quite intrigued. As a rising indie dev, I'm also disturbed by how incredibly similar this game is to one of my own game ideas. Which gave me another idea, just now, that I'm sure many others have had as well:
How about making modding possible later down the line? If not initially, then at least when the game has had its sales momentum. I would love to play around with the mechanics of this game, using this game's existing environments and such. And I'm sure other may want that, as well. After all, moddability is hugely popular nowadays.
Secondly, I'd like to suggest that you add a persistent game mode that doesn't make you want to rush towards the goal, but rathar appreciate every minute of catharsis (similar to a citybuilding game like Cities: Skylines). In such a mode, the main enemy would be the environment and your own bad decisions, and any competing AI or players would merely add to that challenge, rather than it being "first one to the finish line". Now, from a design perspective, I can understand if the game isn't quite there yet (in terms of content) to defend a much slower pace. But it's a thought at least, for later.
Either way, I'm not working on my sister idea right now but, when/if I do, I'll try to avoid being too similar to your game. I think there's a lot of potential for many different kinds of iterations, though.
Keep up the great work!