* Maybe configure lights in separate json file, to allow reuse of consistent models in multiple levels?
* Allow going down to zero seeds by buying lights if a turnip is planted
* Maybe make the mould weaker at the start
-* Display power usage when lights are bought? Also other properties.
-* Maybe also display information next to existing lights (on click?)
+* Display average power usage in light tooltip
+* Maybe also display information next to existing lights -- tooltip?
* Generally balance the levels better and add more levels
* Graphical level selection with screenshots
* Fast forward button for night-time (calculate more steps between redraws; play sounds sped up and with higher pitch)
* Different power usage for different lights (this was already done)
* Different prices for different lights
* Calculate both from # of colours, speed, beam width, etc.?
+* added tooltips for lights