50 Game 2
Comments

What would you say is an appropriate amount of time to spend on this game in a test setting? Would you recommend saving it for last?

For the most part, I find that the amount of time it takes me to work any game in a video is pretty close to the actual amount of time it would/should/could take to do that game on test day. Partly, it's because the amount of time I spend speaking tracks roughly with the amount of time I'd otherwise spend creating a diagram and symbolizing rules.
I would not have saved this game for later. Here's how I think about assessing game difficulty.

The rules about f/z and w/h threw me. Should I think of it as F brings Z and W brings H?

You could correctly think of it that way, but I'd recommend that you learn and use this systematic approach instead (so you can avoid ever having to think through artificial relationships like this one).