These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Space Harrier
Polished Port: The Master System version, surprisingly enough. It manages to keep the feel of the arcade version and adds an actual Final Boss known as Haya Oh - twin flaming dragons who are as fast as incoming obstacles in the tunnel stages. Oh, and they also unintentionally cause Interface Screw because the background Turns Red and makes them damn near impossible to see. Their fireballs are also the same color as them, making the fight Nintendo Hard.
The X68000 port, however, is a mix and match of the Master System and Arcade versions, making it the most "complete" port. It keeps the Arcade version's sound quality and speed while adding in Haya Oh and the "story" from the Master System version. Too bad it never left Japan.