Took me a little while to figure out where to put the .ipk3 file (easiest is ~/.config/gzdoom) but otherwise easy enough to get going using the flatpak version of GZDoom. Installing the regular gamefiles + spear of destiny (from my GOG version) was also pretty easy, but I wonder where one can get Return to Danger and Ultimate Challenge 🤔
Either way, good shout, plays excellently, although seems like hitting enemies is harder in this version than the original, at least when they’re far away.