Jazz Jackrabbit 2 Online

So obviously gems were supposed to give you an extra life. That's what the text in Rabbit in Training says, and that's what they did in 0.98k when you got 100 gems. 100 was also the number of gems to make the gem counter disappear, so that was presumably the highest possible reward. But was it the only reward?

The thing is, the manual makes gems out to be a big deal. Page 14:
Page 29 (talking about the Continue screen):
Page 34:
It's unclear whether this means [[end of level bonuses] and [extra lives]], or whether it means [end of level [bonuses and extra lives]]. Either way, it explains why gems are tallied at the end of the level, even though in 0.98k the extra life is granted right away. But what might those "bonuses" have been?