Ok you have put a lot of work in this and it looks impressive. But it needs a serious balance change. It is far too hard. Currently this may work as a brain teaser for people in the industry or people with computer engineering degrees, but it wont bring any fresh young minds into the industry. The fresh young minds will be scared off.

Teaching is challenging stuff. You have to step out of your current mindset and think with the mind of someone that sees this stuff for the first time. It is not easy to make things look easy and simple. Specifically, I think you need a lot more exploration about cmos logic, about how one side pulls the output up or the other side pulls the output down but they are never on at the same time, about how they effectively amplify the result so the output does not have to depend on the power of the input, etc. Perhaps you can try to have people design things in NMOS logic than in PMOS logic and then combine the two to make a CMOS design to see how they complement each other.

But I do not want to discourage you. This is a very promising start and you should continue if you have the time.

Also, the timed answers -- are you kidding me? The time is waaay too short. And you fail all if you fail a single answer. Oh what is 0xDE in decimal, all I have to do is multiply 16 by 13 and add 14 to that. In my head in 12 seconds. Also the time is not sufficient for filling out truth tables, especially with a laptop trackpad. I was able to pass the truth tables, but gave up on hexracing.

Ok and here are some more specific issues.

-The wires seem to snap in position in a way that they superimpose each other so it becomes very difficult to see what your circuit is doing.

- truth tables seem to be bugged. If you have more inputs than the gate whose truth table you are looking at, sometimes it will generate a fictitious truth table with extra inputs. Thus, some times i get a NOT truth table that has two inputs.

- the ground element should have its connection circle on the top, not the bottom. I realized that you can rotate by pressing R, but the site does not mention that anywhere.