You need the SDL 1.2 library or the "compat" SDL 1.2-on-2.0 library. Arch Linux (in the official repository, i didn't check AUR) has only the latter which you can install with "sdl12-compat" package.
I just tried it in a VM with a very minimal setup (just X server, IceWM and Falkon web browser to download the game) and all i had to do was to install sdl12-compat to make the software rendering version of the game (sdlpetra64) work.