In my eternal quest to find inner peace: yet another silly game, but this time using allegro5 instead of sdl2 (and written in C, rather than really-bad-C++).
This one I think is supposed to be a Galaxian clone.
For the purposes of potential future Android compatibility, I develop this with allegro5.1 locally, though allegro5.0 should also work fine until such time that I actually end up using allegro5.1-specific features.
So, yeah, allegro5 is indeed a mandatory dependency.
Once the dependencies are installed, (along with glibc, gcc, and
make) you'll be able to build spa.
Just run make; this will create the spa binary.