I'm going with April Fools prank now.
If he wanted an "excuse" for why he couldn't finish the game: hard drive crash, virus, somebody hacked him, lost/broke disk where he had all his work saved, etc.
Faking your death on the other hand, all it would take is for someone who knows you in RL to mention somewhere online that you're not dead, and the jig would be up.
You might be able to keep the truth from coming out for a few days--long enough to pull an April Fool's joke, but there's no way you could keep such a deception going indefinitely.