don't say that bro you can totally make a unique game, I just think you should change up the gameplay mechanics so that it's not the same as Luftrausers.
Everybody copies everyone all the time. We can only think of things we've already seen. If it's more blatant in a game competition for fun that doesn't mean it's inherently bad. It's good to change it up, but at the end of the day it's just a fun game.
I see your point but in a competition I don’t think this is the right thing to do, coming up with a game idea is arguably the hardest part, and he didn’t have anything (to my knowledge) saying that he didn’t come up with the idea.