Interesting! Were the crystals two different colors, one for each type of fish? Or did you get the same fish both times?
It has been discovered (I learned from pigletto) that you can obtain both CRISTAL and the small crystals (as well as large crystal if you killed in order) on any level, provided you have precise timing.That's right, I saw a screenshot of that in another thread.

I guess the only difference with what I mentioned is that, since there are still enemies around after forming your first CRISTAL, you can continue collecting letters for your next one before leaving the level.
Presumably it would be possible to get the big crystal after finishing off the little apricots, but I'm not sure about that. If there are other enemies onscreen when the big apricot falls, they'd just disappear and not be "killed." Does forming CRISTAL "ruin the order" like

and similar items? It has never been an issue, but now I'm curious!
Dang... I had a chance to test that a couple days ago, too, but my "grab the letter!" instinct kicked in before my "try something fancy" idea. Oh well.
And now, a sad discovery: If Igor dies while a big crystal is falling down (say, by tripping into a spike pit), the crystal will vanish from the screen but Igor will respawn and continue his happy jumping anyway. So sad to see the little guy in denial.

And a kind of silly discovery:

apparently makes you immune to enemy contact (just like

). You don't even have to touch an enemy with the hammer itself; you can just stand with your back to the fruits and let them walk into you. Somehow, when they fall down after that, they look even more surprised than usual. XD