I have no idea about Roblox, but this game is rather too simple? It’s like you press right all the time and spam by clicking left mouse in a single place. Even if you miss one from time to time you would not die as long as you have points by killing other zombies. I never did that, but I guess that would be terrible easy to write a bot doing that and getting high score without any problem.
How about losing 1/2 of all points (rounded up on half)? Of course it would not help with bots, but it would definitely prevent such tactic for normal players. Another alternative may be adding a cooldown which is long enough to prevent winning by clicking in one place only, so even writing bots would not be so easy?
If people would complain that it’s too difficult then there could be lots of potential stuff to help them not losing points like a shield icon appearing in random place as a reward for killing x number of zombies in a row or something like that.
What do you think about it?