So the submissions say that they will be checked and verified within 3 weeks, but I have a submission for Marvel Super Heroes (arcade) that's still not been verified after 3 weeks. If the currently listed moderator for the game is no longer active then could someone else possible check and verify my run?

The currently listed moderator is not inactive. They were online 2 days ago. Have you sent them a DM yet?

Oh really? Not yet, but in that case I will give it a try then. Thank you

No problem. For the future, you can see when someone last logged in by going to the info tab of their profile.