Real fun. Still don't know f exist appear on random or if you kill that red guys or what :P And on my resolution I saw OVER on the top of the screen i thought it's showing me where to go but when I died it turned out to be part of Game Over text ;p
Red flashing enemies give you health when killed. (See game page) Interesting about that resolution thing, I thought that wouldnt happen, I don't really know how unity handles screen resolutions lol.