What mechanics should I add to my game?

Hi guys,
So I have been working on this game for a week now. It is a tower of hell inspired, medieval style game. I plan to add an item shop, loot crates, quests. Other than that, I can’t think of anything else to add. Feel free to try the game for yourself.

game: [ALPHA] Castle Climbers 🏰 - Roblox

What kinds of stuff will be in the item shop? Look at Tower of Hell and other games inspired by it.