About the game:
In short this is Star Wars episode 4, 5, 6 (the original trilogy) in the world of lego. Everything is legos, the characters, the ships, the actual land - Everything. There are small puzzles, where you have to build items from a pile of legos, push things to the proper location of the ground, and pull levers etc.
Single Player: 7/10
Single player and multi-player are essentially the same thing (as far as I have seen thus far). The reason I rated it so high is there is a total of 18 levels, 10 bounty hunter missions, and a mission called lego city. There are a ton of hidden items needed if you want to go for the full 100% achievement through each of these levels, so they keep you exploring. There are a ton of things to unlock - about 100 characters from what I read, among other things. You can ride animals, and drive star wars vehicles. At the end of Episode V you take out the death star, so the whole level is flying a ship - which was a nice suprise.
Multiplayer: 6/10
This rating might change after I look at the multiplayer options a bit further but I have read on the forums there is no multi-player co-op. I am not sure if there are other game types online, I have mostly only played single player - and am still not very far into the game. My brother was over for a visit today so we tried the co-op mode. It was alot of fun to work together instead of having the second character just being a computer AI following me around, but it was also very frustrating at times. It isnt a split screen multi-player so if you are on the far left, and your friend is on the far right - someone ends up getting bumped or you both just spin your wheels. On more then one occasion I actually died because of us being in different areas of the room.
Graphics/game play: 8/10
Keep in mind that everything is based on lego blocks, so you arent going to get graphics that compare to something like oblivion, but for legos they are looking pretty sweet. As far as gameplay goes I really like the special attacks - for example Chewbacca will tear the arms off of a foe that is close to him. Nothing is funnier then watching a lego storm trooper stand there wondering where his arms went. The movie sequences are actual scenes from the movie - but are acted out by legos, I found myself laughing at this scenes quite a bit - but perhaps I am just to much of a star wars fan.
Achievements: 8/10
I think that the achievements are done pretty well, at least from what I have actually gotten and from what I read. For example the normal 18 levels each have an achievement - which is to complete that level without dying. There are quite a few areas that I can tell you that this will probably be a pretty serious challenge. You have 4 hearts, which amounts to a single hit from an enemy - you can however get hearts back from killing others and destroying various items in the level. I wouldnt call them impossible, but they actually require a little skill to accomplish them.
There are achievements for the lego city and the 10 bounty hunter missions, these are hidden levels - I havent touched them yet so I cannot really write on the difficulty or worth of them but they are based on levels you must first unlock so I think they will be comparable in challenge to the others.
Finally the rest of the achievements is based on the percentage completion of the game (which is related to the numerous hidden items that you unlock throughout the levels) there is one at 20, 40, 60, 80, and 100%, and the points increase the higher in percentage you obtain. With the amount of hidden and unlockable items, I think the 180 points for the 100% is a valuable reward, and you are also rewarded for your work on the way there.
In Short..
The first time I put the game in I was somewhat happy that i rented it. I just thought it was strange, but as I played more I am actually really liking it. I have not gotten very far so perhaps my review is a bit early, but I definately would recommend giving it a chance. Maybe rent it first to see what you think, and go from there. That’s what I am doing 
I give it a 7.5 out of 10
That completes my first review ever, I am not much of a writer 