Thank you so much for this feedback, I really appreciate it. I will fix all those bugs before the next major update.
I believe you can press Esc or the gear icon in the upper right to restart the level or return to the map!
No problem! After checking it again, it is possible to do that in most levels but for whatever reason 1-4 is just missing the pause menu. 
That would explain the confusion. Also I checked, esc doesn't seem to work either. Seems like it needs the settings button on screen to work but I'm no coder.
I will get back to you later once I have some time to try some other levels, see if any other issues show up. But I will happily follow development of the game.
Edit: Also apparently I'm blind, The numbers were there all along.... oops sorry.