"Shadow" may be a bit of a cliché these days, but the game is a decent effort if anything.
Shadow the Hedgehog was one of those one-shotters who we didn't really expect to see again anytime soon after his fall to Earth back in the end of Sonic Adventure 2. Sonic Team came around and brought him back for Sonic Heroes, but this opened up a plethora of plotholes that no game needs, especially if it's a Sonic game. This time, Sonic Team has made an attempt to fill in some of those holes with Shadow the Hedgehog.
Since Sonic Heroes, Shadow has suffered from amnesia. He doesn't remember anything after he and Sonic saved the world and fell from the ARK. Many assumed him dead. Then Sonic Heroes shows Shadow asleep in a capsule aboard one of Dr. Robotnik's (Eggman) flying fortresses. Rouge wakes him up and, together with E-123 Omega, they go to destroy the rest of the Eggman's robots.
We now see Shadow overlookng the city and constantly pondering about just who he is. The city is suddenly blasted by a laser and Shadow is approached by a strange being known as "Black Doom". Apparently Shadow promised to give him the Chaos Emeralds but he clearly doesn't remember. Shadow figures that the Emeralds may be the keys to unlocking the mysteries of his, ahem, "shadowed" past.
The gameplay of "Shadow" is pretty solid. It's sort of like the Jak series, but not quite as refined. Whereas it was easier to use the vehichles and weapons simultaneously in Jak II and Jak 3, the vehicles don't seem to be very useful. I've seen the GUN cars sitting there, but they just are not worth using. The weapons are fine and fix up some gripes that we've seen with the shooting levels of Sonic Adventure 2. There's still the running and jumping and speed is definitely present. Sometimes the game may seem slow, especially if you're playing an "elimination" mission where you have kill all the Black Arms or GUN soldiers in the level, which sometimes requires backtracking, but for the most part it still doesn't abandon its roots. Shadow gains some new abilities: the Chaos Control and Chaos Blast. Depending on whether you've been a good hedgehog or a bad one, the gauges will fill up. Doing good deeds fills up the blue meter, which will grant Shadow the ability to rip through the level for a short time. If you're out doing the bidding of the Black Arms, then you can blow away everything in sight with a huge explosion of energy. Also, there are multiple paths to take throughout the game, which adds to the reply value. The problem is that the military and the aliens don't seem to care whose side you're on, they're going to get in your way and you'll have to mow them down. It's nice seeing Sonic and the gang joining in to help you out, though they don't seem to be useful and I usually keep them around just to keep track of certain objectives if necessary, same with Doom.
The graphics are similar to that of Sonic Heroes. The character models are similar, if not identical, to that of the previous game. The levels are some of the best ones yet with intricate pathways and plenty of details. The game is sort of dark and the colors are not quite as vibrant and most Sonic games are. I wouldn't say they are fantastic by any means, but they aren't terrible. There seems to be some slight slowdown that occurs from time to time, but it doesn't happen often and it doesn't affect the gameplay terribly.
Sound. One of those things that I am pretty much divided on. The music is FANTASTIC. I would love for a soundtrack to come out some time soon. I can't get enough of it. The vocal tracks are one of the main draws, but it's the level music that really seals it. Now the voice acting is truly a mixed bag. The original voice actors were replaced to keep consistent with 4KIds' dub of Sonic X. Eggman/Robotnik had to be replaced anyway as Deem Bristow had passed away. His new voice does pretty well and captures the Doc's personality pretty well. Sean Schemmel (voice of Goku in DBZ) does his part as Black Doom. My biggest complaint are Vector's and Knuckles' voice changes. Knuckles had a much stronger voice prior to this, but he is now replaced by the voice actor for Yugi from Yu-Gi-Oh!. Vector loses the chief detective feel his voice had and now sounds like how crocs tend to be portrayed in cartoons, sadly.
There is plenty to like about Shadow the Hedgehog, even if it still has a rushed feeling and could've used a little more tweaking. The music, as I've said, is great and the graphics are decent even if the graphics engine seems a tad tired and overused. The gunplay at first seemed like it didn't belong with the game, but now I see it could not have worked any other way. Sonic himself says to Shadow "I wouldn't be caught using those things!", but of course this is Shadow. He'll do as he pleases and will reach his goals by whatever means necessary. Besides, I don't think running around in the classic Sonic style would have had much of a point to the game. The multiple paths and different endings will keep you busy for a little while, but probably not long enough. Assuming this is the last major game before the next-gen games hit, Shadow sends the Adventure era of games out with a bang so to speak. Sayonara, Shadow the Hedgehog.