This is a list of quirks and known-issues for specific games, with possible workarounds.
We are currently building and maintaining a list of all known SDL 1.2 games and their current state with sdl12-compat over here:
https://docs.google.com/spreadsheets/d/1u8Rq3LVQYYgu28sBuxrZ371QolbiZu5z_LjENc4ddZs/edit?usp=sharing
More modern builds are ported to SDL2, but the older 1.2 binaries will work on X11 if you turn off OpenGL Scaling
export SDL12COMPAT_OPENGL_SCALING=0
Note that this game calls glXGetProcAddress() directly and likely will not work as a native Wayland app (XWayland works fine, however).
You probably aren't getting usable mouse input, as the game talks directly to XInput2 on X11 (and tries to use /dev/input if that fails). This is not an sdl12-compat bug, as this is going outside of SDL to get multiple mice input. The game is statically linked to a copy of ManyMouse, which provides multiple mice access.
The simplest way to deal with this is change this line in the game's Config.ini file:
CORE_INIT_RI=true
Make that false and it won't even try to initialize ManyMouse, and will use standard SDL 1.2 mouse events for single-player input. (The "RI" stands for "RawInput," which Hammerfight uses on Windows for multi-mice support).
Of course, with this change, you can't have multiple players on the same machine using separate mice.
That game dlopen()'s the XInput2 libraries instead of linking to them directly, so this does not prevent the game from working on Wayland. No XWayland needed!