At this day and age the Nintendo 64 classic is still amazing and brings back a lot of good memories.
If you ever played it, Banjo-Kazooie was a truly amazing game, it revolutionized platforming and was an instant classic. Since the 360 port is pretty much the same game, there are no significant changes, therefore the gameplay is the same. If you initially disliked this game on the N64 and still have the same opinion of it, then I don't recommend you buy this, but I still urge you as opinions will change over the years and maybe you'll like it this time around. If you haven't played it, then you definitely should pick this one up.
The main game is based on an evil witch who kidnaps your younger sister, and you must pursue her through her lair. You enter nine very different and unique worlds to collect jigsaw pieces, or jiggies as reffered to in the game, to open up new areas in the witch's lair. As you progress you'll come across character's, bad and good, in the game's worlds and help them or defeat them to earn jiggies, some of them will teach you new moves and you'll even be able to transform into other creatures. Oh, yeah and did I mention you play as a bird(Kazooie) and a bear(Banjo). You'll also have to reach specific areas or use your moves to reach other jiggies scattered about the worlds. There are ten jiggies in each world and another ten in the witch's lair making for a total of 100 in the game. There are also various other items to collect including musical notes(100 in each world making for 900), honey comb pieces(which give you health increases), and others, such as eggs, which you shoot at your enemies using a special move. All in all the gameplay is very varied and many of the puzzles are very clever and require your full attention. The difficulty is just right and you'll have a lot of fun playing. The controls are also very solid.
In terms of sound, there isn't much to be said. Just like in the N64 game, there is no voices, just a series of sound effects from a character and written dialog as they make their animal-like noises. This can be tedious for some of the characters you talk to, but for the voices you hear more often, such as Grunty's (The bad witch), it isn't annoying. The music is great for the most part, and it's really cool, how there are different variation of the same music when you change position. For example if your in the level normally and jump under water, the music is the same, but the bass is changes to suit your current location, this way you feel underwater, or in a leafy area, or in a dark area, etc. After you do the same move a lot, Kazooie, or Banjo's voice may become slightly annoying to you, but I had no problem.
Graphically Banjo-Kazooie on the Xbox 360 is made better with an HD visuals, improved character models and improved textures. Don't get me wrong though, the graphics look very similar to the N64 version, and the textures are very similar. This is one of the games problems for me. I think they should have made some of the visuals nicer. Some doors or things you would be able to break down sometimes looked like they were part of the background. The game is still surprisingly good looking after all these years, apart some of the textures here and there, the game still feels, and looks fine.
Currently the game is 1200 Microsoft Points on the Game Marketplace. I have no complaints about the price, for this classic masterpiece, and I think anyone who has never played this on the N64 should buy it for sure, or at least download the trial game and try it out. If you were like me and wanted to relive some of those great memories you had with this game back on the N64, then I also recommend you buy it, as you already know it's good and the puzzles will still seem fresh.
In conclusion I had a really fun time replaying Banjo-Kazooie, and would recommend it to anyone who enjoyed the first, as it is still great and you also have some achievements and leaderboards this time around. I've you've never played it then I recommend it to you and you'll have a great time as long as you can get over a few annoying character voices and some occasional bland textures. At this day and age Banjo-Kazooie will still give you an amazing time.