cool man,
https://sjsugamedev.com/gamemaker7 , heres is the old gm if u dont have one, it gets it done to get to 72x72 and doesnt mess the bmp up..
1.create a sprite in it ..hit edit sprite,u will see a green square,click it and u will be in gm paint,go to resize canvas..put 72x72 etc..hit the checkmark u will be back out.
2.up top u will see a folder click it and put your asu rips or whatever in it(hold shift and down or up to select mutliple files),do keep original size,walla they are all 72x72 now,delete the green block..click on your 1st sprite.
3.in the file u got the save as hotkey and next image which is like alt+f down down,u use this for your macro.
mines blocky
well ya no artist
and they are lots for making say war1.
yeah war1 is tuff because they have to be doubled and i blur mine slightly with gm blur setting,otherwise they look like atari sprites lol.
cant find my old macro and the ones on the net are not it! full of malware only or id send a link
currently looking for a way to save the sprites out :/ maybe new gm's have this feature...
it can make them to .gif,maybe somekinda .gif extractor would not screw up the bmp's gone to search.. lots of online ones but none really useful.
..u can try to put it in wargus,it actually plays pretty descent...just needs the music added back to it etc,im gonna see if i can put in a wargus sprite next time gn.