My last run attempt for Best Ending was ruined by the SP Key not spawning in Twinkle Snow Act 3 at the spot above the frosty enemy.

In the past 40 minutes from this post, I tried grinding on just Act 3 to spawn that key in that spot with the failed run. And after 20+ attempts, 0 spawns.

Anyone knows why? Cos I can't be this unfortunate.

The key spawn is decided upon collection of the last chao. If you were just reloading a save state and redoing it over and over, then you likely aren't changing the RNG.

I.. wasn't. I redid the level afterwards to try and spawn the key at that spot about 16 times. And 0 times did it spawn there.

You either are really unlucky, or you already got a key before you approach that spot - note that you can only collect 1 key per attempt of a stage, and with any given spawn, there are SEVERAL. So in a given attempt at a stage, if you collect ANY key from the set, then the rest of the keys in that set will no longer show up.

This means if you did get the 50-50 layout, if you happen to collect ANY key in an earlier portion of the level, then the key above the frosty enemy will NOT show up because you already have one. You'll know if you got a key at all by looking below your life counter. This isn't relevant in a proper best ending run since the keys won't spawn until after you get the last chao, but if you're just repeating act 3 over and over with all chao collect already, then you're likely collecting a key on the way anyways and you're not noticing.

If this isn't what you're doing, then I don't have any other explanation so you're either leaving something out or you're really really unlucky.

If you have other questions/discussions, then please ask in the discord channel, as you can get more direct responses there instead of several days later - we don't check the threads that often.