120k is ideal for 5K CCU. If I were you, I would make the shop areas more visible and game pass prompts more frequent somehow, like if a user is taking long on a level or a user dies, they are prompted to skip/revive. I did not play the game.
more creative ways to monetize, like paying for a sneak peak, or a echolocation perk kind of how some blind people can see, maybe you can pay for some mario kart thing to pick you up if you fall?
things that will make the game more interesting or difficult such as harder levels is what you want, likely not something paid which will make the game fun, it should be doable on its own, a game called specter sells game difficulties, you could do the same with levels
Either make the gamepasses more expensive or make more of them as the max amount someone can spend is just about 600 robux. For comparison, my semi-p2w simulator (I say semi as I sell alot but it just loses value as you can get it f2p) makes around 500+ per paying user and often gets to 4 robux per dau.