Under DOSBox, with IBM PS2 option (#3), the font of the In%, Out, and Time is different, and the toolbox looks different. Also, the levels slowly fade in and out. The levels themselves look different, though (EGA only?)
The 4th option (forget what it's called) looks like the 1st (normal PC option), but the mouse didn't seem to work.
Under normal XP, I can get the levels to load under High Performance and IBM PS2, with the same results. The screen flickers but the level never starts, and the mouse doesn't work. The toolbox, font, etc. is the same in both of these modes.