I’ve only heard mention of Hydroplane once in the past, but it was never confirmed that it even existed as far as I know. I’ll assume Mike mentioned it in an interview somewhere...
Here’s Owen’s response about the mystery proto:
So no, I do not recognize it.
But not Triple Hunt, because it is two players, and we did not have a two player mode.
Also, it looks like this would use a left/right control. Im guessing the * drop down the screen, and the goal is to catch them before they hit the bottom.
Cool idea, but I have never seen that before.
But if you find out, let me know! :-)”
"One of these days, I'm going to cut you into little pieces!"- Nick Mason, Pink Floyd