I've heard many times of Kriegspiel, and I'm curious to know what kinds of hints there are. I don't know if I have the memory to play a game that way, but I'm sure it's an intriguing challenge. Progressive Chess sounds utterly horrifying to me. I imagine games don't last longer than a few turns. And I've heard of Smess as well, and hear it's an intriguing game. It's honestly amazing how many underrated games there are, such as Smess. I remember reading in a book years ago that Smess looks a bit whimsical and may sound simplistic, but it's actually a complex game. I think it'd be fun to try sometime as well.

You should try out self eliminator chess. I doubt your students program the AI, do they? Simply programming the moves sounds pretty straightforward. You should give it a whirl. If you're ever interested, I'm sure you've noticed that some of us are playing correspondence games here, and I know RicOlie_2 and I are both interested in Self Eliminator.

If you are into that sort of thing and ever find the book I mentioned, it's worth a look. I just found my copy and realized that I misspelled his last name: Schmittberger. It only mentions the softer version of the game where your only legal move must be accepted. Honestly, I kind of like the idea of one legal move being a loss. Like you said, it balances out, and you shouldn't have accepted a move that put yourself in that position!