HP6 is like playing HP5 with a different story, new side missions and an improved dueling system.
Now when we look at this game from graphics point of view, we can easily see that EA Games has done a great job in making the character models which look very life like and the environments are made with a lot of detail. The whole of Hogwarts castle and the grounds are made with precision and look exactly as in the movie and as described in the book. Other than Hogwarts there are also two other places where harry takes a visit which includes the weasley's burrow and the horcrux cave which are, like Hogwarts, made to look like their movie counterparts.
The Hogwarts environment is huge and is as responsive as well. For Example, you can't go in the water of the lake but that doesn't mean that the water is just a picture and will not respond. When you throw a rock in the water, it splashes. Similarly if you are standing at some steep high area and can't go down doesn't mean that if we throw a rock at the slope it will disappear. But it stumbles down the slope. These were a few things which really impressed me.
A fault in the graphics is that they are not improved and are the same as the order of the phoenix. The graphics in the PS2 version (I really don't know about the other consoles) lack a certain crisp that would make the look of the game more fun. And another thing is that sometimes the frames of the video become a bit slow which could be a bit annoying but doesn't matter that much.
Enough talk from the graphics point of view. Now we start on the Gameplay and Controls. The controls are pretty much similar as the one's in the order of phoenix. The rotating camera function is added which I think I probably didn't note in the fifth game. The spell casting controls are the same i.e. using the right analog stick as your wand performing different gestures. However, the charm spells are reduced to only four spells i.e. the levitating spell (wingardium leviosa), the repairing spell (reparo), the pushing spell (depulso) and the fire igniting spell (incendio). The lessened number of spells is notable but doesn't matter because the other spells from order of phoenix such as the breaking spell (reducto) and the pulling spell (accio) weren't really that important. Also the game makes up for these lessened spells with it's advanced, improved and "better than order of phoenix" dueling method which I will describe later. A "run faster" feature has also been added in the controls which be used when you want to get somewhere quick. In the previous games, harry's friends always dangled along with him but in this game, he travels solo except for some story missions. In the order of phoenix, we had a list of places in Hogwarts. When we selected one of these places, footsteps appeared on the ground leading us to the place. This was very annoying as the footsteps were hard to see. In this game if we are lost in a mission and don't know where to go or what to do, we can simply press the select button to summon the ghost nearly headless nick, who leads us to where we have to go. Also we can select a place in the list of Hogwarts places and nick leads us to it which makes exploring a lot easier and less annoying as Hogwarts is big and easy to get lost in.
Now moving on to the story missions. The story missions are very less and if you continuously do the story missions without taking interest in side missions, the game feels very short. This is hard to prevent and it is also easy to prevent. This is because in free roam mode, it's not like you go to a place or talk to a person and then the mission begins and after completing the tasks you go back to free roam mode. It's feels more like you are in a mission after doing a mission. For Example, if you finished some quidditch story mission, you have to go to the next mission with ron, but as ron doesn't normally stick with you, it feels like falling from story mission into story mission. Although, the story missions are interesting and fun and are honest with the movie. The cut scenes are all lacking enough information for anybody ,who hasn't read the book or watched the movie, to understand the plot of the story but they are pleasant to watch.
This game also has the a free roam mode like it's predecessor. We can roam around the whole of Hogwarts including it's ground, it's classrooms, it's castle, it's corridors and also the towers. This could be a lot of fun because there are so many places in Hogwarts and they are all beautifully designed. Since Hogwarts is too big, it's hard to remember passage ways corridors and other stuff and it is very easy to get lost. This is where the nearly headless nick factor comes to play as he easily leads you to your desired location.
Other than story missions there are three side missions i.e. dueling, potion making and quidditch. The dueling club is very interesting and very well improved. In the fifth game, we just had to cast spells with different gestures with the analog stick until the other wizard stopped, and there was no telling when the other wizard would have stopped because there was no health gauge. In this game the spell casting is improved and it also has a proper health gauge which has shining orbs which glow dim on damage and then disappear. The spell gestures are different and more practical than that of the fifth game. We can cast a quick spell which can also be rapidly shot i.e. the stunning spell (stupefy). It is casted simply by tipping the right analog stick forward. The other spells are the disarming spell (expelliarmus), the paralyzing spell (pertrificus tortalus), the "hang your enemy by his feet" spell (levicorpus) and also the shielding spell (protego). We also have the ability to charge our stunning spell to make it more powerful. Dueling is improved greatly and this is very good as enemies will be in your way when you are fulfilling your mission task or stopping slytherin house students from bullying other students or dueling might be a task itself. Also there is a dueling club for each Hogwarts house where you can practice your skills, learn new spells and become the champion of the club. There are some challenges which will help in earning awards in the form of badges. These tasks include ordinary stuff like becoming champion of all houses' clubs or finishing a duel without a hit taken. Yet there is one challenge that annoys me which is the "lose an event 5 times and replay". This is very annoying as it doesn't make any sense. There is also a multiplayer dueling feature in which you can duel with your friends using different harry potter characters like ron, Hermione, luna lovegood, malfoy and many more.
The potion making game is also a lot of fun as it includes adding different substances until a certain colour is achieved and stirring the mixture and heating it. Also adding thing after shaking them and only add if shaken properly or else smoke fills the room. If any mistake is made, the smoke appears and has to be cleared. There is also a time limit to this and the potion must be made in time. There is also a potion making club where we can make different potions. Sometimes potion making is a story task. For Example, making a punch in slughorn's Christmas party, or making an antidote. There are badges in this club as well and it does not include the "fail in the event 5 times" badge.
The quidditch club is very abysmal when compared to the other mini games. All you have to do is fly around and pass through stars for time until harry automatically catches the snitch. The only fun feature is that you can bump into the opponent seeker when he is closing on the snitch, but this doesn't last very long. Quidditch matches are sometimes story tasks and they don't get any less annoying. The quidditch club also has badges including the "fail the event 5 times" badge.
The last side story mission is collecting Hogwarts crests. There are some 150 crest out of which 25 are gained by collecting many mini crests which can be obtained by casting the pushing spell on glowing objects all over Hogwarts. The rest of the crests are whole and can be found in obvious or secret places of Hogwarts. Sometimes we might need to solve a simple puzzle to get an unreachable crest, like hitting an object at the crest which is very high to make it fall. Collecting crests will get us rewards like increasing the power of spells in dueling or unlocking new characters for multiplayer dueling.
So wrapping it up, we can say that harry potter and the half blood prince is an amazing, beautiful and well put game. It's like playing the order of phoenix except with a different story, different side missions and improved dueling system. It is a very good game which even the people which are not harry potter fans will enjoy. But I personally expected it to be better because it is the same as the fifth game even though it is the sixth game. And the quidditch could have been done a lot better, although, it could be replaced with wizard chess found in the order of the phoenix!
My ratings for this game out of 10 are:
Gameplay 8.00
Controls 7.25
Graphics 8.50
Play Value 7.50
Game Length 4.75
Overall 7.25