Harmonix does it again.
Cons: Some glitchy/awkward animations; Currently small support for keys and pro mode; Some keys parts are flat-out boring
Note: This review is written without playing pro mode. I think the addition sounds cool (although I highly doubt its educational purposes given that it mostly lets you replay other peoples' songs), but like it will take a lot more practice than most Rock Band instruments. Since I'm already learning guitar, keyboard, and drums on my own I didn't feel the purchase was necessary. Sorry for those who expected a deep rundown on pro mode.
They laughed at us and said "learn to play a real instrument" knowing that the one thing these games would not bring us was real musical skill.
Look who's laughing now?
In any other rhythm game, this simulation component would make or break the experience. But Harmonix is a special case of a rhythm game company, because even if you never touch the pro modes in your life this is a must-play rhythm game.
Name any issue you had with past Rock Band games. As long as your issue wasn't disliking the game in general, I can say that the problem has most likely been fixed. Hated pausing in the middle of the game? The song rewinds a few seconds to replay you up to that point. Annoyed by a long and repetitive career mode? The new goal-based one is condensed and more varied. Needed to leave in the middle of a song? A drop-out option is now available for everyone. Or perhaps your friends constantly wanted to change characters. The brilliant addition of individual menus allows each player to change characters quickly and easily between songs. This reviewer was particularly impressed to finally find an option for individual scrolling speeds for each player finally. Harmonix has thought of virtually every tiny problem with the past games and easily set the new standard with this entry.
Not just that, but they've added whole new ways to play. Most obvious is the keyboard, which is pretty neat, giving you access to a whole new part of supported songs, but ultimately similar to guitar/bass. That is until you take it to the other new mode, "Pro mode." This option, available for every instrument sans vocals (who get harmonies instead), seeks to replicate the actual instruments you are playing as accurately as possible. This opens up more keys on the keyboard, distinguishes cymbals and toms on the drums, and requires an actual guitar controller for guitar and bass. Once again Harmonix shows great foresight in allowing guitar/bass parts to be played on keys (since the current selection is limited) and vice versa (although in many cases the key parts are kind of boring). Admittedly no such concessions are made for pro modes, which are generally limited save drums.
To top it all off, the song list is giant as ever, and the goal oriented turn the game has taken ensures that you always have something to do. Many songs or groups of songs have achievement-esque goals (some of which are achievements) challenging to you to five star them on certain instruments or perhaps hit certain sections or use overdrive a number of times (I was pleasantly surprised to find a goal for vocals on early DLC release "El Scorcho" even). The career mode takes this a step further by challenging you to earn spades by completing whatever goal the game gives you during the song. By completing these challenges you earn new clothing for the game's somewhat revamped character creator and fans (which are tracked regardless of mode now).
The animations and character creator have been redone, allowing greater customization than before, and a higher level of detail in how your characters move, but this is where the game's most obvious issues lie. While the game doesn't have much in the name of game-breaking glitches or bugs, there are a number of animation issues, particularly where the often-jittery keyboard player is concerned. They don't take away from the enjoyment of the game much (it IS a game about note highways after all), but such issues are a disappointing oversight in an otherwise phenomenal product.
And to top it all off, regardless of what DLC you might have at this point, the tracklist is pretty great. There are some genuine classics and some great indie songs, and while some choices are questionable (such as "I Can See For Miles" as The Who choice), they usually turn out to be pretty fun. It's rare that a game so nearly perfects a genre, but make no mistake, Harmonix has nearly done that for the rhythm game genre with Rock Band 3. Make no mistake, if you are interested in music games, this is the one to grab; it's hard to see them getting much better than this.
But then again, we don't really know what other tricks Harmonix has up its sleeve.