New discovery:
In TEST Level, there's that giant overripe banana that walks around everywhere. And it will walk into that pit, but it will continue to walk into that wall until it eventually goes through it. However, I have found that if you stomp on it for your first time, you will get 2 coins (1 for stomping on the banana-man and another that appears after you stomp on it). But if you do it a second time, you will get 3 coins (2 for stomping on the banana-man and 1 that appears after you stomp on it). Do it a third time, you will get 4, and so on. This leads me to beleive that there isn't just 1 Shine in that level, but 2. I'm currently attempting to get that hidden 2nd Shine (in TEST Level). More news after I get 100 coins.
EDIT: I'm at 99 coins. I'm about to get the 100th coin... awww... crap. The game froze. It froze when I touched the coin, so it seems that the programmers didn't implent 100-coin-Shines until after the test level.