Episode 1 takes the Half-life 2 games in the right direction. We can just hope the episodes can continue doing this...
The story of episode 1 takes place directly where Half-life 2 left off. You had destroyed the Citadel's dark-fusion reactor and seemingly defeated Dr. Breen. Unfortunately, in your moment of triumph, the G-man extracts you from certain death, leaving the new heroine, Alyx, to die. When episode 1 begins however, you are suddenly plucked away from the G-man by your alien allies- the vortigaunts. You wind up buried in some wreckage when you return to the real world, but Alyx and her robot pet Dog quickly manage to find you. You quickly come to disocver the current situation, and set-out to delay the citadel's imminent explosion, and escape from City 17.
The basic gameplay here is completely unchanged- Valve ain't fiddling with a winning formula, and we can't blame them. The shooting action here is still quite sharp, the arsenal having all the general stuff you'd expect, including the trademark gravity gun, and ever popular crowbar. You'll be facing most of the same enemies you faced in Half-life 2. Combine soldiers, headcrabs and zombies, antlions, and more.
Episode 1 does introduce two new enemies for you to face- there's the "zombine" (The term being coined by Alyx when you first encounter these guys). These guy's main feature is the fact that they can draw out a grenade to use as a club against you. Of course- they always activate this grenade- effectively making them entertaining suicidal fighters. Then there are a few stalkers you also have to deal with. You glimpsed stalkers in the original- but you never really saw their capabilities. Their most annoying ability is to hinder your progress in the citadel by attacking you with red beams, and even destroying the orbs you use to solve various puzzles in the citadel.
Other than these two new foes however, episode 1 offers absolutely nothing new, and completely fails to improve in several areas that Half-life 2 desperately needed improvement. For starters- enemy soldier AI is as bad as ever, with no signs of any attempts at improvement by Valve (Talk about lazy). Its been stated that allied AI has been improved as well, but thats ultimately not saying much. Alyx makes a great partner, but she did just as well in the original game, even though you fought with her only briefly... The only difference is that she has some new unique attacks against certain enemies, particularly zombies, but this isn't AI improvement- this is just improvements of her capabilities, and could of easily been included in the original game.
What episode 1 DOES manage to do however, is skillfully dodge those previous complaints with some extremely sharp level-design. Much better than the level design of the original game. The enemy AI issues are dodged due to the fact that soldiers aren't nearly as much of a dominant enemy in episode 1 like they were in the original game (The dominant enemy now unquestionably being the zombies). Allied AI issues are also dodged since your backtracking alot less often now- so they don't get in your way nearly as often here. Its all great stuff, that more than makes up for several of the game's faults.
Graphically, Episode 1 still looks great, with the new addition of HDR. Other than this, the graphics look pretty much similar to what you saw in Half-life 2- great character models- great particle effects- the same old yet still great looking environments... Thats the only complaint to be had here- the environments on hand are all what you saw in the original game. But hey, why complain when the environments here still look excellent? Sound wise, the game sounds excellent, just like the original with great voice acting and sound design.
When all is said and done, Episode 1 may offer more of the same, but it offers it in a sharper package. Albeit- a much shorter package at that- but whats on hand here is higher quality than what you saw in Half-life 2. So if you liked that game- you'll love episode 1.
Pros: Spot-on level design that skillfully masks over many of the game's AI flaws. Shooting action is still sharp. Graphics and sound work are still excellent. The zombine is an entertaining new foe.
Cons: Enemy soldier AI is still lackluster. Being a mere episode- the game is very short by nature.
Recommendable for: Liked Half-life 2? You'll love Episode 1. Standard FPS fans should also like Episode 1, though its short length is a bummer. You'll probably want to play Half-life 2 before getting episode 1 to understand the story.