Can you dress up in a costume while attending the attraction?

Thanks for all the answers guys

yes but nothing too big/bulky (like big wings or stilts), also no masks

Yes. They may just ask you to remove a fully covered mask before entering like they did me.

Yes, you can attend in costume

I would recommend giving them a call. I don't think any of the guests were in a costume. Update here if you did happen to give them a call. Other people might find it helpful.