Not the best port of the game, but still a fun to play.
If you did receive the game when purchasing Madness Returns though, it is worth playing to understand the back story of the second game. Provided you accept the game as a product of the time it was created, it is quite enjoyable.
While the game looks like your standard third person action adventure game, it controls a lot more like a first person shooter. This is not too surprising given the background of the developers and the fact that the game was built on the Quake engine.
Unlike modern third person action adventures where melee attacks have a fairly wide strike, making it easy to hit near by enemies, the attacks in this game are fairly narrow so manual camera management is a lot more important in combat than you might expect. With attacks bound to both face buttons and shoulder buttons though, this isn't too difficult to manage with the PS3 controller though.
Another difference between this game and more modern ones is the scarcity of check points. The game will auto-save when you enter a new map, but that is about it: if you want finer grained checkpoints you need to manually save. This isn't too bad on the PC version of the game where you can use the Quick Save and Quick Load keys, but they didn't map these commands to any button on the PS3 controller so you end up having to pause the game and go to the save menu instead. For some of the later levels where a misjudged jump may result in instant death, this breaks up the flow of the game a bit.
Despite these niggles, the game is still fun to play. While the graphics are dated the level design is imaginative and varied through the game. The storyline is not particularly deep, but the re-imagining of classic Alice in Wonderland characters keeps things interesting. And a number of these characters carry over to the second game, so it is interesting to see how they have developed between the two games.
For the most part, the difficulty curve is fairly smooth: the only exceptions are one or two boss fights which can be quite challenging even on easy difficulty. But given that you can save during the boss fights (you could even save after every successful attack if you want), they aren't insurmountable.
Overall, I'd say the game is worth playing. If you have bought Alice: Madness Returns and never played the first game, then redeeming the code and playing the first game should provide a richer experience when you play the second.