Hai guys. While making mask map I usually use second layer - heightmap - to make good mask map. Use layers in multiply mode. By the way, good way to make realistic mask maps, lol. Anyway, I forgot turn off heightmap layer. Opened game, loaded map and... lake texture was black, actually every lower part were dark. It looked cool, so now I know, I can make mask maps darker, looks gorgeous.
So did you find any easter eggs which would - or maybe should - brake your game? And did you learnt something from them?