Entertaining, if only for a short while
I've never played a Sims game before, only SimCity, SimEarth and SimAnt. I got the game from gamefly and played it for around 1 week (~7 hours of play time in total).
The graphics: Meh. Of course thats the way I've felt about everything on the Wii. I have a pretty good TV, which I'm sure gives me a more negative opinion than I would have with my old TV. Overall if you don't spend a lot of time staring at individual elements of the game, you'll be fine. Everything is identifiable, but of low graphical quality. One thing that bothered the most was how some of the plants were just..wrong. For example you harvest hibiscus off of a vine on the ground, when really it grows on a tree. Lack of attention to detail like that irritates me in a game.
The gameplay components:
Harvesting: This is one of the main activies in the game. You need to harvest lots of everything you see, which is not a problem bcasue there's so much stuff. Seriously, it's like a freighter bearing thousands of seeds from every plant crashed on this island..it's a little ridicoulus. Occasionally you'll need to reposistion yourself, even though you could see the harvest prompt. On a harvesting note make sure you get soft wood every time you pass a papaya tree, you need a ton of this in the game and its fairly rare.
Relationships/home life: A little tedious. Typical stuff like using the bathroom, eating, sleeping, etc. The problem is you frequently need to open the menu which takes time. It doesn't take a ton of time, but it adds up. You can choose how many Sims will join you..I recommend one. I played with a bunch of them and realized that 98% of the time they were doing nothing. 1% of the time they do their job (fish, gather resources, etc) and 1% of the time they waste some critical resource just as you're about to construct something. Overall the only use for the other sims is to keep your social level up, which you could do with your monkey minions.
Crafting: Annoying as hell. Some items require a craft bench, some do not. Each time you craft something you'll need to go through a 3 step menu process, which gets tedious. For some stupid reason I did not see a means to craft more than one of something. For some items you'll need 10 ropes..which means 10 items that three step process.
The story: I was fine without the dumb llama temple story line and ignored it. Personally I would have prefered a black smoke monster and a bunch of mysteries..but thats just me.
I think this game should have an online component, that would make it much more fun, especially given the limited means of communication available to the Sims. Perhaps from some sort of premade communication menu to prevent any poor behavior. I really thought of this game as a lot like Monster Hunter Tri without the monster killing. You're just wandering around picking up tons of materials. I found the game mindlessles fun for about 3 hours, focused fun for about 1.5 (when I decided I was going to finish it before sending it back to Gamefly) and tedious for the rest of the time. Overall I'm not sad it came to me from Gamefly, but I wouldn't consider buying it. After about 5-7 hours you're completely done with it. It was nice in the sense that I could just lean back on the course and do something that had no consequences for a little while.