Array is not allowed in DataStore?

Hey there! I'm having a bit of trouble dealing with DataStores. While trying to initially set the values for a player, I am given the error: Array is not allowed in DataStore. I was wondering what I was doing wrong and if someone could inform me in which path to take to correct this. Thank you!

This is a regular script located in ServerScriptService if that is of any use.

local dataStore = game:GetService("DataStoreService"):GetDataStore("GeneralStatsTest")

game.Players.PlayerAdded:connect(function(player)
	local key = "playerTest-"..player.userId
		
	local kills = Instance.new("IntValue", player)
	kills.Name = "Kills"
	
	local deaths = Instance.new("IntValue", player)
	deaths.Name = "Deaths"
	deaths.Value = 1
	
	local credits = Instance.new("IntValue", player)
	credits.Name = "Credits"
	
	local getSaved = dataStore:GetAsync(key)
	
	if getSaved then
		kills.Value = getSaved[1]
		deaths.Value = getSaved[2]
		credits.Value = getSaved[3]
		
	else
		local valuesForSaving = {kills.Value, deaths.Value, credits.Value}
		dataStore:SetAsync(key,valuesForSaving)
	end
end)

DataStores can only save raw values, like strings or numbers. To save and load an array, you have to encode it into a string before saving, and then decode it upon retrieval. Thankfully, Roblox includes a tool for this: http://wiki.roblox.com/index.php?title=JSON

Also, when using GetAsync, you usually want to wrap it in a pcall(), just in case it fails. https://wiki.roblox.com/index.php?title=API:Class/GlobalDataStore/GetAsync