Disclaimer: This is my opinion on the game, given what I have played. If you disagree, that's fine, not everyone shares the same thoughts.
Ok, this is going to be more of a rant than a review, but oh well. I might as well get the bad out of the way first before I talk about the good.
Calling this game a Pac-Man game is a travesty. Pac-Man goes around a maze, eating pills, fruit and ghosts. In this game, Pac-Man goes around the world in a non-maze like fashion. I can understand that, many games transition between genres and dimensions. However, this is where the game stops being Pac-Man entirely. Pac-Man goes around, collecting spheres, not eating, and defeating ghosts by scaring them, and chomping them, collecting their eyes in the process. Pac-Man also goes around collecting fruit for arcade machines in his high school. Sorry, high school? I thought Pac-Man was married? In fact, more to the point, I thought Pac-Man was a man? Yep, in this game, Pac-Man is in high school, his voice unbroken for some reason and no wife anymore. Mrs. Pac-Man does not exist. The best part about the high school? 1 classroom. Ok, I'm digressing. Pac-Man, with the help of his 2 friends and his professor, Sir C, and Inky, Pinky, Blinky and Clyde (yep, the 4 ghosts who constantly chase Pac-Man in previous games to kill him) go around the world to stop Betrayus and the ghosts. This is explained in the first cutscreen, along with terrible voice acting. Surely it wasn't too difficult to make 3 people act surprised at the same time? Then the game starts. The mouse is over sensitive, so the camera shakes around too much, and since you rely on the camera position to go forwards, Pac-Man stumbles around like he's had 10 too many drinks. The scare mechanic is worthless as every ghost can get chomped with or without it, and for some reason, Pac-Man has to grab handles with his mouth and pull them down using gravity. Oh, are hands too difficult to program? Also, for health regen and to unlock god knows what else, you eat cheese and pies. Way to stick to the canon.
Ok, so after looking at this, I need to include a section on the game itself, no comparison to the older Pac-Man titles. Here goes: Pac-Man and the Ghostly Adventures controls like Banjo-Kazooie or A Hat in Time, but I find the turning with the mouse to be too sensitive, and Pac turns too much, meaning I never move in the direction I want to, but that could be a problem with my laptop not having the RAM needed for this game, or whatever is needed, I'm not good at computer technical things. As for Pac-Man's abilities, he can scare enemies, and chomp them. The scare mechanic seems useless, as the ghosts get chomped in one go anyway, scared or not. As for the chomp mechanic, you'd better be pointing the right direction, otherwise Pac will just chomp in the direction you've pointed, even sometimes chomping right next to the ghost. As a platformer, Pac-Man jumps a little too low, meaning obstacles you'd be able to clear in other games, such as the previously mentioned A Hat In Time, you can't clear. Pac also has access to teleporters, which he uses and poses after coming out of them, stopping the flow of the game, and making me regret buying this even more...
If this game was a different IP, perhaps Banjo & Kazooie or Crash Bandicoot, I could have accepted this game better, as the gameplay suits the character, and they already have distinct characters in the universe without having to name different coloured Pacs and give them all different hair. And perhaps the controls are good when using the 360 controller, but I don't know about that unfortunately.
Although the game is a good concept, it falls flat on every single level except enemy ghost AI. I suggest getting Pac-Man Museum (see edit below) to play an actual Pac-Man game, and I suggest playing Banjo-Kazooie or Donkey Kong 64 for a good 3d collectathon platformer. I hate to say this, but I hope this series of games dies before Pac-Man gets the same tragic fate at Banjo & Kazooie did under Microsoft.
[Edit] I no longer suggest getting Pac-Man Museum, just get Pac-Man Championship Edition, it's one of the two games from the museum I really recommend, the second being Pac-Man itself.