Double-click flag so that the music syncs! (The og song is a cover of Final Destination with Soldier and Demoman!) You can replace characters by going into their costumes and replacing the poses with your characters' poses. You can also change some of the animation code if you want it to look different.
My boyfriend and I play WAY too much 2fort. Big credit to @DeanDaCat and @Squiggly Tuff for the og project! I had a ton of fun doing the soldier sprites..