Sonic the Hedgehog 2 is a game I hold very dear in my heart: it was one of the very first games I ever played for the mega drive, and I enjoyed every minute of it. Although considering I was 6 years old at the time, I died constantly...but that never largely got in the way of the fun of playing the game. Despite dying enough to make the "game over" screen forever etched into my brain, I enjoyed Sonic 2 immensely.
Then, when I saw that Sonic 2 was out on the XBLA, my nostalgia factor kicked in and I promtly downloaded it, ready to control the energetic blue hedgehog once more. It seemed like the perfect buy for me: a classic game plus little extras and achievements to boot.
As far as the actual game goes, the classic mega drive model has been completely unaltered. You play Sonic (or Tails if you like defying titles) as you progress disjointingly between the different stages and constantly defeat Dr. Robotnic (or Eggman as he unfortunatly would later be called).
As far as the standard 2-D platformer goes, Sonic 2 is still as good as ever. Running across the screen at mach 1, collecting rings, correctly timing jumps and avoiding animal controlled machines whilst listening to a brilliant polyphonic soundtrack (especially the 'Metropolis' song) is still as fun and rewarding as ever.
Another point that I will forever praise and worship for this game is an implemented save system. Since the older sonic games never had a save or password system, trying to collect the chaos emeralds was a difficult task. Now, you can simply save just before you start a bonus stage, or perhaps in the middle of it, in case the great mines of doom become too much to handle. Hence, becoming Super Sonic (which I could never accomplish back on the mega drive) is made easier, though the challenge of the actual bonus stages are present and still as unforgivingly difficult as ever.
Though with the introduction of a save system comes the reducdancy of the life system. Though this is due to the fact that the actual game has been unaltered, knowing that you can just save before the final boss or something similar and then just load if you die eliminates one of the core challenges of Sonic 2.
That said, the platforming challenge of correctly timed jumps and the monsters themselves are still present, so don't think that the game will be a simple walk in the woods.
As I said before, the soundtrack for this game is excellent, with most of the songs sounding like energy pumping rock scores which complements the game very well. Then the final boss track sounds like an orchestal score with a blaring snare drum in the background that creates this wonderful epic feel and fits the final fight greatly. Though my favourite by far is the metropolis song, purely because it sounds like a kick ass rock song and it really gets you going for playing the stage.
The monsters range from near harmless to downright cheap. An example of harmless would be the fish from the emerald hill stage; just as long as you jump either on or at them, they're destroyed. The example of cheap is the grasshoper from the metropolis stage. His attack is throwing his scyths at you. This is cheap because most of time these monsters are situated in cramp low roofed areas where jumping in order to dodge the scyths is impossible. Not only are they hard to dodge: they are fast, can curve in the air; and at times go 180 degrees to catch you if you somehow managed to jump over the grasshopper.
Despite the little complaints of the enemies or the near total loss of the need for a lives system, the game is still really damn good. With wonderful level design and a retro aesthetic complete with a great soundtrack, you can't go wrong with Sonic 2. If you're looking for classic fast paced 2-D sidescorlling adventure, a bit of nostalgic indulgence, or just something to tide you over until Sonic 4 is out, this is must buy.
So now I leave you with a little question to ponder on: why did Sonic the Hedgehog 1 have 6 chaos emeralds, but every Sonic game after that has 7?