For one thing, it was made by Hudson Soft of Bonk and Adventure Island Fame at the permission of Nintendo. The game originally was developed for NEC PC-8001. It was later ported to the Sharp X1 in 1986. The game was also hacked into NES format.
The original games had 2 major changes aside from levels. These were a flick screen, this cause game play to change with koopas now bouncing back from the side of the screen even if there wasn't a wall and also has a limited color palate and faster speed causing the timer to drain alot faster. There also is the hudson soft bee in the first level which enables continues.