It's good, but it's not 'all stars.'
The game is supposed to feature pretty much every wrestler to ever be in the WWE, but it doesn't. The roster is even smaller than that of Smackdown! vs Raw 2011. It does feature the most prominent legends and current wrestlers, but there are some missing too, so the title can be a bit misleading.
The graphics aren't very good for the PSP. The effects in finishers and signature moves are OK, but the wrestlers look like their faces were painted on, and their mouths don't even animate. The graphics get the job done, but the previous wrestling games on the PSP had facial animations as well. This game doesn't. The wrestlers are expressionless.
The sound is a similar story. Commentary is available in the PSP version compared to the previous games on the PSP, but turns out it isn't as welcome as we thought. The commentators - Jim Ross and Jerry 'The King' Lawler - don't say a lot of stuff except stuff about stopping the match and the match being so violent, and they repeat themselves a lot. Voice acting in Path of Champions mode is good. The sound effects and voices in matches are awful.
The gameplay is a huge change from the previous games - the game has a bigger focus on combos and unlike the previous games where only the Square and Circle button were used for attacking, all four face buttons are used for attacking. Gameplay is fun even if it's a bit slow.
The game also has Path of Champions and Fantasy Warfare modes. Path of Champions is just like Road to Wrestlemania, while Fantasy Warfare lets you pit present wrestlers against legends to decide who deserves titles like, 'Greatest High Flyer.' (If Jeff Hardy was still in the WWE, he'd have my vote.) Fantasy Warfare mode is excellent.
WWE All Stars is worth playing if you were enough of a fan to buy the previous games on the PSP. Still, Create-A-Wrestler mode is limited, entrances don't have fireworks or lighting, and the graphics aren't anything special. Then again, gameplay is fun and the Fantasy Warfare mode is great.