Stupid question, but what does the default init program do? If I have a single application (say a game), can I just set up the file system, statically link my game and bundle it as an iso, rather than say containerising it?
Purely academic.
Purely academic.
Containers work similarly, except that they don't take the whole system down when their PID 1 exits. That's why containers often don't have a process manager inside, but Linux based operating systems do.
Do anything necessary from there to boot your game, and record those steps in a script. When that's done you can just point your init cmdline to that script (doesn't even have to be a binary, a script with the #!/bin/bash shebang should just work).