It is all perfectly fun (if only sort of tennis related), but the way you get to these events isn't nearly as enjoyable. The map is organized with a trail on it, one which takes you from event to event, but you only get to move on the map with "tickets" which number one through four and thereby denote how many spaces each one will take you. If you play too many events (minigames) at the spots you land on, you'll become rundown and potentially injured, but you may not have any choice about what you do due to the ticket availability (you must participate on the event on any space on which you land). There are special spots where you can purchase more tickets (one each time), but this all makes too much of the focus of a tennis game non-tennis related things. Imagine if you could only play tournaments in Tiger Woods by landing on the right square or could only play a baseball game in MLB 2K11 the same way. You don't need to land a ticket for the exact right number of spaces to play in a major, but for other tournaments you do and that's hugely frustrating for anyone who wants to build their tennis player by playing tennis.
Once you do get to play tennis, the actual mechanics of it are good, if a little dumbed-down. There are several basic types of shots you're allowed to hit (lob, top spin, regular), but anything more specific is game controlled depending on your position on the court. It makes you look like a much better player than you might be at first, but as you progress, you'll find that it really hampers you in trying to accomplish what it is that you want to accomplish on the court.
There is no claim that this is an EA Sports-esque title, one that would do its best to imitate the actual real-world sport, but Virtua Tennis 4's desire to do so sometimes and even then in only halfway fashion makes it something of a disappointment – if you're not able to/don't wish to license all four Grand Slam tournaments in tennis, don't build a game mode which revolves around you going to knockoff versions of those tournaments, particularly when the path to get there involves things like having to serve soccer balls into goals on a tennis court while being blocked by plastic defenders.