add a leaderboard or something to give people an objective

I think it's a bit fun, plus a time killer.

It was better than that other Ninja one I saw but it would be nice to have a gradual step in difficulty not this just aim towards the player every N seconds with Y many faces

Very challenging, but it looks like it was made a decade ago!
Use just a bit better sprites, lay off the MS Paint, and use a bit of color and you got a pretty good time waster!

This is the same idea as the "avoid ghosts" game that was posted a few days ago. Except this time it's executed even worse.