Is there a way to cancel a function while it is running?

So I want to cancel this function so when all the players die but how can I cancel a function tho?

function StartGame()
	ChooseGame()
	print(rm)
	game.ReplicatedStorage.PlayersAlive.Value = game.ReplicatedStorage.NumPlayers.Value
	for i,v in pairs(game.Players:GetChildren()) do
		v.Backpack.inGame.Value = "Game"
	end
	game.ReplicatedStorage.GameStatus.Value = "Game"
	if rm == 1 then
		game.ReplicatedStorage.GameStatus.Value = "Game"
		local WaterRunMap = game.ServerStorage.WaterRun:Clone()
		WaterRunMap.Parent = game.Workspace
		game:GetService("ReplicatedStorage").GameTime60:Fire()
		game:GetService("ReplicatedStorage").WaterRun:FireAllClients()
		wait(2.5)
		for i,v in pairs(game.Players:GetChildren()) do
			v.Character.HumanoidRootPart.CFrame = CFrame.new(-207.5, 17.5, 151.5)
		end
		for t = 60,0,-1 do
			game.ReplicatedStorage.GameTime.Value = t
			wait(1)
		end
		EndGame()
		Intermission()
	elseif rm == 2 then
		game.ReplicatedStorage.GameStatus.Value = "Game"
		local BombBombRainMap = game.ServerStorage.BombBombRain:Clone()
		BombBombRainMap.Parent = game.Workspace
		game.ServerScriptService.BombRain.Disabled = false
		game:GetService("ReplicatedStorage").GameTime60:Fire()
		game:GetService("ReplicatedStorage").BombBombRain:FireAllClients()
		wait(2.5)
		for i,v in pairs(game.Players:GetChildren()) do
		v.Character.HumanoidRootPart.CFrame = CFrame.new(-43, 2.5, 27)
		end
		for t = 60,0,-1 do
			game.ReplicatedStorage.GameTime.Value = t
			wait(1)
		end
		game.ServerScriptService.BombRain.Disabled = true
		EndGame()
		Intermission()
	elseif rm == 3 then
		game.ReplicatedStorage.PlayersAlive.Value = game.ReplicatedStorage.NumPlayers.Value
		game.ReplicatedStorage.GameStatus.Value = "Game"
		game:GetService("ReplicatedStorage").GameTime120:Fire()
		local SwordFightMap = game.ServerStorage.SwordFight:Clone()
		SwordFightMap.Parent = game.Workspace
		game:GetService("ReplicatedStorage").SwordFight:FireAllClients()
		wait(2.5)
		for i,v in pairs(game.Players:GetChildren()) do
		v.Character.HumanoidRootPart.CFrame = CFrame.new(2, 5, 80)
		end
		for t = 120,0,-1 do
			game.ReplicatedStorage.GameTime.Value = t
			wait(1)
		end
		EndGame()
		Intermission()
	--[[elseif rm == 4 then
		local PlatformRunMap = game.ServerStorage.PlatformRun:Clone()
		PlatformRunMap.Parent = game.Workspace
		if NumPlayers.Value == 2 then
			print("PlaceHolder")
		elseif NumPlayers.Value == 3 then
			print("PlaceHolder")
		elseif NumPlayers.Value == 4 then
			print("PlaceHolder")
		elseif NumPlayers.Value == 5 then
			print("PlaceHolder")
		elseif NumPlayers.Value == 6 then
			print("PlaceHolder")
		elseif NumPlayers.Value == 7 then
			print("PlaceHolder")
		elseif NumPlayers.Value == 8 then
			print("PlaceHolder")
		elseif NumPlayers.Value == 9 then
			print("PlaceHolder")
		elseif NumPlayers.Value == 10 then
			print("PlaceHolder")
		elseif NumPlayers.Value == 11 then -- Sometimes roblox's servers can go 1 player over max So this is for that player 
			print("PlaceHolder")
		elseif NumPlayers.Value == 1 then
			print("Not Enough Players for gamemode!")
			print("Ending game!")
			PlatformRunMap:Destroy()
		end
		--]]
		elseif rm == 4 then --This Map is disabled Because it is a wip
		game.ReplicatedStorage.PlayersAlive.Value = game.ReplicatedStorage.NumPlayers.Value
		game.ReplicatedStorage.GameStatus.Value = "Game"
		local LaserTagMap = game.ServerStorage.LaserTag:Clone()
		LaserTagMap.Parent = game.Workspace
		wait(2.5)
		for i,v in pairs(game.Players:GetChildren()) do
			v.Character.HumanoidRootPart.CFrame = CFrame.new(104, 7.59996033, -35)
		end
		game:GetService("ReplicatedStorage").LaserTag:FireAllClients()
		wait(10)
		for t = 120,0,-1 do
			game.ReplicatedStorage.GameTime.Value = t
			wait(1)
		end
		EndGame()
		Intermission()
	elseif rm == 6 then --This Map is disabled Because it is a wip
		local SewersMap = game.ServerStorage.WIPSewers:Clone()
		SewersMap.Parent = game.Workspace
	end
end

I want to cancel this function