I just released a minor update to termtris (v1.4) which should make it easy to fix this bug. I added a BINDIR variable in the makefile, to specify the binary installation directory (bin by default). If PREFIX is set to /usr and BINDIR set to games, it should do the right thing.
This release also fixes a crashing bug in the joystick code, so it's worth updating. http://nuclear.mutantstargoat.com/sw/termtris/termtris-1.4.tar.gz or: https://github.com/jtsiomb/termtris/releases -- John Tsiombikas http://nuclear.mutantstargoat.com/
