You forgot to add several things for the leaderboard to work. Here's the fixed script :
game.Players.PlayerAdded:Connect(function(plr)
local stats = Instance.new("Model", plr)
stats.Name = "leaderstats"
local lev = Instance.new("IntValue", stats)
lev.Name = "Flying Points"
while (wait(1)) do
lev.Value = lev.Value+1
end
end) |