I don't think it has to be in-depth. I just made an implementation of Blackjack in Python. The rules are very easy to code up, and the AI (the dealer) is actual

I don't think it has to be in-depth. I just made an implementation of Blackjack in Python. The rules are very easy to code up, and the AI (the dealer) is actually hard-coded by the rules, so no nasty trees or recursion. It also allowed me to demonstrate my knowledge of object oriented programming, program design, etc. I would probably recommend something other than a mostly HMTL/CSS website because that doesn't show off your programming chops very well. Don't stress about it too much!