I'll start off simple by saying I enjoyed Dead Island Riptide from start to finish. Lots of different weapons to choose from such as pistols, rifles, maces, swords and almost anything else you can think of. The game kept the first edition's upgrade//repair/create workbench in which you can repair your gear, upgrade the stats on a weapon, and even create exotic weapons from the given materials unlocked by blueprints scattered all over the map and different quests. The game still gives you that wonderful free-roam experience in which basically you can do whatever you want provided you can get there. I really liked the zombie dismemberment immensely on Riptide. It's a wonderful feeling to lop of a zombies head while he's charging you or take out his arms making you a good ole fashion zombie penguin.
The combat is FP shooter and melee of course with addition of more bombs and mines for a more tactical defense. All in all you will have a great time exploring the big map trying to find all the collectibles, blueprints, mini bosses, and side quests. Also on a bonus note you can upload you character from the first Dead Island if you played it.
So where my game didn't meet a perfect score was with the non depth story and characters and all of the fetch for side quests. I know I know that if its not broke don't fix it referring to the first Dead Island but I expected more from its sequel. The game play was great for the most part but the collision detection was so rough. Jumping up things was such a chore and I felt a little too constricted at times. The game also made leveling a breeze by letting you turn common materials in for experience in which I thought was too easy. The MP has way too much friendly fire. I couldn't tell you how many times some kid joined my party and continued to kill me with a modded weapon. The luck factor completely blows as well. I got near every achievement and went everywhere on the map multiple times and never could find any high end rare gear. Why make it that hard? I've already beat everything and no rare weapons dropped or found then I have no incentive to play anymore. You could say the game lacks replay value in that sense
In conclusion if you played the first Dead Island and enjoyed it then you will enjoy Riptide for the most part. On the other hand if you played Dead Island and wasn't crazy about it then don't expect much different. Now if you haven't played either then you really should because they are different from most zombie games in that they are generally more free-roam while having a level scaling allowing any player to play with any other. And not to forget the hours of zombie dismemberment and making exotic weapons to get the job done one, maybe two and who knows, maybes three zombies at a time.