They basically made a full game and then cut it out to sell in different versions. The Grand Slam edition is what a regular full tennis game used to be back in the days. Looks like devs made the game but executives on top ordered to chop it off to make more money.
Top Spin 4 is one of my all time fav sports games. It had awesome gameplay, presentation and a fun career mode. This lacks a decent career mode based on what I am reading in the reviews. Will be sitting this one out, especially at full price. What a shame.