Found a game breaking glitch.
This sucks. I'm at the upper rightmost guardian and got surprised by the enemies there, so I flew up to the above screen. I planned to drop down on the opposite side and try my luck. Before I left I managed to kill the first two enemies in my sights, and when I came back all I found was a black diamond I could touch and one half buried in the ground, with the guardian missing. And this was my final guardian too... way to go with the programming error, I'm giving this a 0/0 out of frustration for wasting an hour on this. I'm not even gonna try it again for fear of encountering another glitch near the end of the game again. Cya, good luck on yer next game.