There was a game I played years ago on here, it was a side scroller, similar to Terraria/Starbound, it's a pixel art game, the character had a round face sort of like a an astronaut helmet (it could've been just that) and the only word I remember from the game/game name is Moon, I believe the developer was from the UK

I want to find it and play it again but I just can't seem to remember it and find it

Well, good luck then. Maybe the game was properly tagged. If it is good, it might be under the first few pages in popular. Unfortunately, you cannot combine name search with tag search. 

https://itch.io/games/tag-pixel-art/tag-side-scroller