But please don't call for donations. I've bought/preordered a number of linux games already, but I'd never ever donate to a for-profit company. Just call it preorders and ditch everything below the full price.
Indeed, that looks nice...
One question regarding the alpha video on indiedb:
It seemed to me the enemies reacted once you got into a given range, which made it fairly easy to spot them from the screen's corners, even more so on widescreen.
Just my 2 cents, I thought it may make the game, especially single player, less challenging. Have you considered addressing this?