Hi Maintainer, I was able to get it building again, at least on the ppc64el machine I tested, by not using with -mno-altivec.
Builds both with Sid and Ubuntu Kinetic, if you use my patch from bug 1004616 and no longer set -mno-altivec. See also this commit: https://salsa.debian.org/games-team/performous/-/commit/de72e1dfae743adb65a444341872bda06d6941e7 Is -mno-altivec still required? -Dan