I designed this game for my friend's MSc thesis, he showed with this template some of the Android SDK's physic engine potential.
This is not a completed game and (unfortunately) will be not released.
(but if you are from a mobile game publisher company and see some option for releasing, write me ^^)

The main menu has a very simple UI with three buttons which is simplyfies the UX.

We don't want the chapter select menu to be too complex, but want some maps, so I designed it just for medium-large devices, not thinking too much what if someone see this screen in a 3" display. That is why the UX is a simple 3x3 grid, at big displays works very well, the back button is clearly understandable and visible in the left corner.

 

The gameplay screen. I checked the current same genre games in the Play Store, App Store, Windows Store but have not too much influence so I needed to figure out the UX. As you see, we find this version for the best. Left top corner is a play button (which starting a train and checking the bridge's strength), a pause button and an edit button. The edit button giving up the right side menu, where can we build the bridge, clear it or undo it. Clearly understandable icons with yellow color, which is visible in every map.

As you see in the chapter select menu, we have 9 maps, influenced by popular mobile games. Each map has unique jack point, where the bridge need to connect.