That's relatively common... if the company isn't full of dick bags you can usually get specific carve-outs. Nobody gives a shit about the game you're programming on the side - they're just unfamiliar with corporate espionage laws and being overly defensive.

At EOD any real lawsuit is going to pretty much ignore any NDA that isn't hyperspecific. I mentioned in another comment that I signed an NDA preventing me from disclosing the contents and parties in another NDA... that's highly fucking enforceable, and it's necessary because normally surface level information about contracts aren't considered secret knowledge. But all the ones we programmers sign are nearly completely horseshit - not because you can freely violate it, but because disclosing proprietary business practices is already illegal unless explicitly allowed.