Very frustrating at times, but a fun game overall
The two spots where the game fails are 1. City Design and 2. Mission Difficulty.
CITY DESIGN
San Andreas is huge. Vice City would just be a little town in San Andreas. There lies the problem. The city is too big and there are lots of country roads and deserts. Sometimes, you wind up in the middle of nowhere with no car and you have to tap X for about 10 minutes to run to the nearest town, which can be a long ways away, just to find an automobile. This is not fun, it's frustrating.
While the ability to swim is awesome, sometimes it's aggravating. When you are driving too fast and you fall into a river or lake, sometimes you have to swim for about 15 minutes to find land. Then, you might be in the middle of nowhere, and you have to run around for another 10 minutes looking for a car. Spending a lot of time making no progress in the game.
MISSION DIFFICULTY
Yes, majority of missions are easy and beatable within 3 tries. But what I mean by difficulty is that some missions are so frustrating, you may want to stop playing all together. Racing missions come to mind when you have to win first place in a street race. Also, some missions require you to drive all the way across San Andreas, which is a long haul, and if you fail (or complete the mission for that matter) you are stuck on the other end of the city and must get back to where you were doing your missions.
Most missions are plenty of fun, some are very difficult but fun to keep trying.
Some missions that are very hard are pointless, and add more aggravation than fun. Fortunaltey, the most frustrating mission is an optional one.
Overall, it's a great game. Lots of improvements over Vice City, it's very enjoyable, but very frustrating at times. It's worth a buy.