Is is possible to get a BLU version? But I guess that would be more work than simply color-swapping the characters' team colors, because the background would have to be changed as well to show the BLU base.
Great composition, and I love the "nostalgic" background effect.
The only thing that I noticed is, Soldier seems slightly, very slightly, too large compared to the other characters, esp to Sniper and Heavy. He should be smaller than Sniper, Demo and Medic. Maybe because Soldier is standing slightly higher, and in front of Sniper? I don't know.