This game looks great. Unfortunately, my GPU went up to 100% and the game lagged so much I could not even walk around. I do have a slower computer, though it's not common for even small Unreal games to need a lot of effort to optimize. I've played text games in Unreal that are literally just a picture and text and it still puts my GPU up to 100%. I don't use Unreal myself, but have read that reducing frame rate and having far away items not be rendered until they are approached can help a lot.
Anyway, congrats on finishing your game. It looks like a lot of people have enjoyed it :)