Oh, no reason. Wanted some things to stick out a bit more like the detail put into the platform. 

mixed resolution= some pixels are regular sized, some are double sized

 I didn't intentially use mixed resolution. Unless you mean the lighter area? That's supposed to be sunlight. 

what was your reason for using mixed resolutions?

Insult yet a complement. Thank you. ;)

Wow.... would have never guessed this was from you.....

 thought this was bigger :( Dissapointed. Looks still good.,