At least in DOSBox, I noticed that after exiting the game, the keyboard isn't working anymore. Could it be that the keyboard interrupt hooking isn't properly reversed at exit? Also, when launching from a small launcher program, the games never properly returns (could it be that there are other interrupts that are hooked by the game, thereby potentially messing up the caller's stack)? Other games work fine with the launcher (using DOS int 0x10, 0x4b). When running in DOSBox Debugger and launching from my launcher, after exiting something like this is printed:
...
CPU:Illegal/Unhandled opcode 0F00
CPU:Illegal Unhandled Interrupt Called 6
CPU:Illegal/Unhandled opcode 0F00
CPU:Illegal Unhandled Interrupt Called 6
...
In case of not using a launcher (running ORBSALV.EXE directly from DOSBox), I don't see these, but the keyboard stops working.