A simple batch script for single step flattening a series of delta frames converted from GIF89 animation to PNG.

flatten.bat

@echo off

setlocal

set itemno=%1
set outno=%1

set /a outno+=1

SET itemno=0000%itemno%
SET itemno=%itemno:~-5%

SET outno=0000%outno%
SET outno=%outno:~-5%

convert out\xbox%itemno%.png -page +0+0 xbox%outno%.png -layers flatten out\xbox%outno%.png