Alright, so items are getting implemented now as well. He had trouble with making sure that, once you reached 99 duplicates of an item, that it didn't roll back over to 0 and he found a function already existed to solve that.
What items should this game have? We already have both potions. Hopefully a sewing kit is the first. Then maybe some temporary stat-boosting items like a whetstone or something to speed stamina regen.
Depending on how/if elemental/non-physical damage types are implemented, you have things like
Bolt Paper/Gold Pine Resin (add lightning damage to melee weapon 60s)
Fire Paper/Charcoal Pine Resin (add fire damage 60s)
Green Blossom (+stamina regen 60s)
Probably something that assists specific H situations, like something to make Aradia easier to preggo up
Consumables that you can use to increase her Souls/Blood Echoes
Bombs of different types, most likely fire damage, an upgrade to it, and some variant that deals another type like lightning (lighting urn) or magic (hexing urn
Throwing Knives, longer range, lower damage, saves MP, can carry a ton, are great for baiting things that are waiting on the wall or roof (at least when you were able to lock onto them in the games proper...)
Throwable aggro item (Alluring Skull, Pungent Blood Cocktail)
Poison curing, possibly include a bleed build up cure as well as toxic cure
An item to let you safely return to the church