It's just too damn silly.
When you have the premise of "Domhnall Gleeson tries to kill James Corden", it is a bad idea to not have the film end with Domhnall Gleeson actually killing James Corden. I wanted to see James Corden's rabbit corpse hacked to pieces by an insane Domhnall Gleeson but instead I just got extreme mediocrity. You have failed me yet again, Sony.
I NEED this to be a long running series of horror movies. So, to make it easier for Hollywood, I'll come up with titles
Greta 2: The Greturn
Greta 3: The Greckoning
Greta 4: Greta's Got a Brand New Bag
Greta 5: Gretuation Day
Greta 6: The Gretables Have Turned
Greta 7: Gretakes Manhattan
Greta 8: Greta Works In Gretail