So the design in my head has a "scene" at the top of the screen with the generators to be purchased underneath... much like Idle Skies...
There are several ways to go with this... 2d... 3d... low poly... pixel... etc.
Found this doing some research... this looks quite good actually...
came across these two kits... I'll have a play with getting these into unity and start the process of getting a self playing pinball machine going... I'm thinking I might have to move my scene side by side to the generator menu because a pinball game is long... not square...