I think you can make it as challenging or not challenging as you want. Just implement a simple Forth or Lisp in Lua and make a cute little game with Love2d or even just a simple text game.
Maybe I expect too much from people but like at least being able to write a simple tree-walking interpreter is basic computer science education and who hasn't tried to make a game at least once?
The problem is more that some people just like sharpening the saw and some people like cutting down trees. Both are valid. Some people get really into programming languages and tooling but never ship any product or vice versa. But people need to be skilled enough to do both.
I think I might be the one to expect too much on second thought.
Making a language and a game is one thing, making a good language and a good game is something else entirely.
Very few people can do either of those on their own, let alone both.