J.K. Simmons is a stellar actor and is doing a phenomenal job on the VA as far as I can tell.
What is really hurting is the corny writing in this game and the cartoony art direction. It is really hard to come from Elden Ring to this cartoony game.
I don't think the writing is an issue here or it is corny. Elden Ring has barely any nonoptional writing. For the most part, you can play the game without talking to any NPC or doing their quest line and still finish the game.