EDIT: My actual review. Sorry for it being so long. I tend to overdo things
Gameplay: 10/10
The simplified shot controls and on-screen helps are a smashing success. With the helps I understand how I should be hitting all the different possible shots in all the different possible situations. The shots all feel natural and very satisfying.
The development of a point has taken a huge step forward from TS3. It now follows more closely how a point would develop in real life. There are a good variety in the types of points. There were some short points when a player hit a good serve and followed by wrong footing his opponent on the second shot. But you also need to be able to construct points in order to win.
To sum it up, this is exactly the direction the series should be going. It exceeds the expectations I had for the game in this department.
Single Player: 9/10
I am not a big fan of single player, especially when it comes to tennis games. However, they did a very decent job. I played it on very hard and definitely could not just waltz through the whole thing. But even more than that, the matches were short enough (if you play normal mode) so that the career did not drag on, and I kept wanting to play just a little bit longer so that I could get to the next status level in my career. It reminds me very much of the career in TS1.
I would have scored this an 8, but I am going to give a bonus point for not requiring me to play the career ever again if I don't want to once I complete it. Along with allowing people who do want a long career the option to choose full matches. Both very good long run choices.
Add to that the great lineup of pros and an unlockable "Expert" level, and you can have a good time trying to win some exhibitions against the AI with some interesting matchups. The singleplayer definitely has a solid shelf life.
Sound & Graphics: 7/10
The graphics are basically the same as TS3 in my opinion, maybe ever so slightly better. However, the licensed players are rendered much better than they were in TS3. The signature movements, especially on ground strokes, are very good and make you feel as if you are actually playing with that player.
The sound is definitely a good step forward for the series. The clanging of rackets on a stretched-out shot, and the increased anticipation of the crowd on a long point are great additions to the game. There are a few out of place sounds, like the coach in the Academy that keeps repeating the same lines, sometimes twice in a row after one shot. The music isn't bad, at least it probably won't get annoying like some of the TS3 songs did. But then again, you listen to any song enough times on a load screen and you probably get tired of it.
Online: 8/10
This is the biggest part of the game for me, and also the area where I am the most critical. True there isn't much you can do when it comes to online competition in a sports game besides tinkering with the ranking structure.
First and foremost, it is really unacceptable that the Top Spin series still does not have a viewing mode for online matches (doesn't even need to be live, maybe just the grand slam finals could be replayed), ranked doubles, or even 4 console doubles exhibitions.
I am also not a very big fan of the ranking structure that has been used for TS3 and now again in TS4. True, tennis is made up of tournaments, but it just doesn't feel right in online competition. A ranking structure should motivate you to work hard on your game and give you a sense of how you compare to other people, but the TS4 system fails to give me any of that. Really a simple rating structure like TS1 and TS2 had would ultimately be better. On the other hand, the tournament structure does reward the best players more quickly, but it ultimately ends up being a race of who can play more quick matches in a 1 week period. It ends up being a matter of quantity over quality. I could play a bunch of matches and finish in the top 10, but I will never be able to know how I truly compare to other players in overall skill.
They did add back in a rating level for quick matches you can use to chart your progress. And there is even a leaderboard for this, though it is hidden under a "secondary statistics" category. To me, this is the true test of skill in the game. It is a little unfortunate this skill rating is attached to your character, so that if you change characters the skill rating gets reset to 0.
The addition of an icon in world tour to let you know where players are waiting helps you to find a match and the matchmaking seems to work well. If you want to get online right away with your level 5 character, you can do so and get matched up against another custom character as close to your level as possible. However, sometimes that may not be very close since each lobby will only have a few different players to choose from. The creation of tournaments detracts from the potential of a really good matchmaking system by creating a lot of small lobbies instead of putting all the players into a single lobby and getting a lot of good matchups.
Finally, the 2K Open is a really great idea. In the past the pros were basically irrelevant for online play and relegated to noobies who wanted to do exhibition matches. However, this has the potential to attract people to play online pro player matches and try out different pro matchups. It adds an extra dimension to online from just the standard ranking. I'm not sure it will maintain interest in the long run, but for now it is an enjoyable diversion from strict competition.
Playability: 9/10
The simplified control screen and on-screen helps do a lot for helping you get into the game right away. The problem with TS3 was that you could get turned off very easily since it was so frustrating. The elimination of errors every time you mistime a shot will get more new players to stay.
I'm a little worried about what this could do for the depth of the game on the competitive side though. It seems like this won't be a problem, since online matches I played had a lot of variety still. As long as a dominant go-to play and/or playing style doesn't develop, there will be a tremendous amount of depth to the game.
Overall: 8.7/10
A very solid game. Though the online ranking structure could be rethought in terms of what gamers are looking for in online competition, all-around the game is very successful in its development from the previous title. It should be able to maintain interest from a wide range of players over a sustained period of time. Highly recommended.