That 'fog' was still at the main-screen & actually breeze of air passing by from right to left. Cool, I guess we're thinking of the same (which you plan to re-draw by hand later)?
Maybe I'm bit too detailed, because it's just a fragment of your game, anyway custom-keys sound cool too (hoping they'd work, not referring to double-features like fading in/out the same subtextline, inventory, etc.? I had that issue if copypasting and IDs being identical)
I mean, the arrows are right just 4 directions, maybe hitting space for progressing or interacting, jumping ...just if a player likes to go in those directions / heading straight, that qwrty/azerty will work anyway, was at least my thoughts of 'using additional keys'.