Both games use the same tecnique and are made to run at 50 fps without ever dropping a frame. What do you see, exactly? Is the screen refresh less fluid or is the game slower altogether? Maybe something's wrong with your equipment (settings)? Hopefully we can solve the issue.
Congratulations on solving the issue!
(I had suspected that it might be NTSC, hence my question about the game being slower.)
Yes, the game is indeed difficult, but that's mostly because it's a single level (zone, in the game's terminology) as it had to fit in 16 kB. QUOD INIT EXIT IIo will have 5 zones of increasing difficulty.
Enjoy!