I think this game could be made better quite simply through visual indicators, like animations and sprite changes. By making there be a visual indicator of how far the skeleton can attack within, and have a swinging animation to show it killing the knights, it can be made better already.
However, I suggest that instead of reducing points to prevent spamming, there should instead be a cooldown meter. This allows you to remove ugly visual indicators like showing how far it can attack, and creates for more interesting gameplay. Different enemies can be created too, like a bulkier enemy that can move back and forth. A parrying system could also work if this enemy attacked by shooting projectiles.
Other than that, and what FortuneCosmic mentioned, it can definitely be improved, but it isn't a game to give up on.