Before I talk about Mass Effect 2, I have to warn you that I am going to complain about a lot of things in Mass Effect 2. And then I am going to give the game a score that does not seem to match my complaints. If I am a little harsh or upset about certain features in this game it is not because the game is bad, but rather that my expectations of what this game COULD be are so high that I feel they were not even nearly met.
Mass Effect 2 picks up two years after Mass Effect 1 ends. The Council has brushed off everything that happened in the first game as a simple attack by the Geth. Of course, we know this is a blatant lie. In addition, human colonies on the edge of the Terminus Systems (colonies which are not technically protected by the Citadel Council) are being attacked and everyone in those colonies are disappearing without warning. This is obviously unacceptable. So you, as Commander Shepard, have to go find out what is wrong because every other being in existence would fail on a mission like this.
Everything about Mass Effect 2 feels cooler and better as you start out the game, but as time goes on and you are asked to do more and more mundane tasks in order to get upgrades and recruit team members, the game really starts to fall apart. It's not that the game isn't fun or that the core gameplay erodes or anything of that nature. The gameplay itself is not only fun, but a massive improvement over Mass Effect 1, with tighter controls and more sensible combat situations. But in many scenarios a lot of what could be considered story elements become boring and repetitive, making the game feel significantly simpler than the first. Where Mass Effect was an epic space opera with an unlikable antagonist, expansive missions in many open playing areas and team members recruited along your path who mostly share your goals, Mass Effect 2 is more like a 40 minute episode of Star Trek where the crew must infiltrate and destroy a Borg cube and pick up a few people along the way. The antagonist is ambiguous, the missions start to feel contrived (go recruit person X, something is bothering person X so go do a mission for them), and the goals of your team are simply unknown by the end of the game except that they may or may not be "loyal" to you.
It is clear that BioWare made many improvements to the game, although the PC version of the interface is clunky and unpolished. The inventory system has been all but removed. When you find items along your quest they will either modify your current set of armor or be added to a weapons locker where you can switch out your weapons between missions or at specific locations within them. Unfortunately, switching weapons is a massive pain compared to Mass Effect, partially because the UI used to do so is clunky and needs some definite improvements, and partially because the differences between specific weapons are often unnoticeable while your main weapon in that class simply gets upgraded during the game and there is no way to know from the weapon screen what the advantages and disadvantages of each weapon are because they no longer use a damage-based system. Instead, your damage is based on upgrades researched and the weapon list presumably follows the "top is crap, bottom is great" philosophy of UI design. While these changes do greatly simplify what was an overcomplicated system in Mass Effect, it also loses a lot of power in user customization. Yes, you spend less time worrying about your weapons and armor overall, but you also pretty much look the same (and feel the same about your character) the entire game.
If you want to upgrade anything along the game and don't feel like cheating the system, you'll be required to do the most mundane task in the game: scan planets for minerals. First, in Mass Effect, minerals were nothing more than the basis for an achievement. I never collected all the minerals, and I never felt like I was missing out by not doing it. In Mass Effect 2, you have to collect minerals or you won't be able to finish the game. Scanning is done by putting an indicator on the planets surface, moving your mouse around and watching a meter for mineral content. Then you fire a probe and collect your minerals. In order to get all the upgrades you'll want, you'll spend several hours completing this process over the course of the game. While this certainly is a simplification of the Mass Effect process of collecting materials by driving around on the planet's surface and hunting for mineral deposits, it replaces a completely non-essential part of the first game with something absolutely essential to completing the game.
This just describes even more in-depth the problem with how they've gone about changing things. All of your weapon and armor upgrades go through a research terminal on the Normandy. So, while the inventory system has been simplified, you still have to do mundane things to get better weapons and armor on your character. Additionally, technology has apparently gone backwards since Mass Effect since now the Normandy requires refueling constantly and weapons require thermal clips to fire instead of simply overheating. People have also apparently learned that grenades are useless as there is simply no way to collect, carry or even fire them unless you train a specific biotic power.
Having clips for weapons does improve the overall combat experience since the clips reload faster than the overheating system cooled down, but it would have been nice to have the overheating system as a fall back in case you ran out of ammo in a weapon. In terms of weapons, though, the roughly 50 weapons you can have in the game are interesting and, as far as I can tell, none of them appeared in Mass Effect so they are new. You even get to use some Collector weapons which look sort of organic, although they mysteriously also use thermal clips. A nice addition is ammo powers. Disruptor, Incendiary and Cryo ammo all make your weapons do different kinds of damage, and they can be turned off and on at-will, even during combat. This makes fighting different kinds of enemies interesting, although the disruptor ammo is by far the most widely applicable damage type so there is very little reason to try the others unless you want to. Also in Mass Effect 2, you get biotic powers whether or not you had them in Mass Effect. The advantage here is that you actually get to try out biotics yourself, even though aiming biotics doesn't make any sense and they often miss ultimately making the biotic system feel tacked on to the standard cover-and-shoot gameplay.
The leveling system in Mass Effect 2 has been completely overhauled. Where Mass Effect had tons of skills that could be leveled up and were crap at the beginning of the game for no reason, Mass Effect 2 has far fewer skills that can be upgraded. In general, this is a good thing as it makes no sense to be unable to hit a barn with a pistol near the beginning of the game. You're supposed to be the most elite military man in the universe. Still, I appreciated the more incremental style of the upgrades in Mass Effect. Leveling in Mass Effect 2 is meaningless for the most part as all you gain are skill points that you can use to PURCHASE skill upgrades. Every skill has 4 upgrades and each of them cost the number of points for their level, so level 1 upgrades cost 1 point, level 2 upgrades cost 2 skill points and so on. The end result of this is that you cannot upgrade all your skills in your first play through, which is good and bad. Good because you never feel like the game is TOO easy, but bad because you never feel like you did everything you could do.
Along with that, the game attempts to force you into plot missions and away from side missions as often as possible despite the fact that you probably have a good reason for avoiding the plot missions: there are hardly any of them. You can easily reach the end of the game with only having recruited a portion of your team and doing none of the loyalty missions. In fact, the game seems to try and coax you into this path. Without a clear antagonist and any clear reason prior to later on in the game to actually complete plot missions, it is difficult to feel any emotion about taking too long to get to the end of game mission (the location of which is obvious from about ten minutes into the game). This is even more annoying for two reasons. 1) The speed at which you complete the main story has a minor determining factor in the end game, and 2) the number of loyal crew members you have has a major determining factor in the end game. Yet the game tries to make you choose between these two paths as often as possible. There is one point later on in the game where you have to do things in a certain order as fast as possible or it has a major impact on the end of the game... and it leads right into the end of the game so you can't do any more recruiting or anything past that point.
To kind of wrap up the entire gameplay, I should mention the missions and worlds you play on. Overall, the worlds look great. The skylines are nice and the areas are quite believable. Unfortunately, this seems to have come at quite a cost as playable areas are extremely small. When you enter a mission, you are taken to a map unavailable during regular gameplay and as soon as you are done with the mission, you leave that map. I didn't have trouble completing any of the missions, except for a couple where you pick up random items and have to figure out where to take them. This makes the regular playable areas on each world feel unnecessarily small and limited and also prevents you from admiring some of the more extraordinary beauty of places like the Presidium on the Citadel. Sadly, this means there are no really interesting areas like Ilos in Mass Effect; all the areas are too small for something like that.
In passing, I'll mention that the graphics are almost above reproach. While characters still often appear to run with steel backbones and molasses legs, the overall model appearance has improved dramatically. Additionally, the vistas out of windows or on approach in the Normandy are quite good looking. The cut-scenes look wonderful and the world designs are quite nice and believable. Even the Normandy has received several enhancements and visual upgrades and the Normandy itself is much more interesting in layout and design than it was in Mass Effect for reasons that become clear shortly into the game.
To wrap up now, everything I said above may seem like huge issues, but overall they really don't affect how fun the game is. Mass Effect 2 is a great example of a well made, great playing and great looking game from this generation. I simply had lofty expectations based on how good the first game was. The scope of this game is far smaller and it comes off feeling more like Mass Effect 3: Prologue than a sequel to the first game. While many improvements were made and the game often shows you why it is better, you constantly run into smaller things that either didn't need to be changed or shouldn't have been added and it does affect how the game feels, even if it doesn't really affect how the game plays. As a rather crude example of this, between Mass Effect and Mass Effect 2, every single control outside of the standard WASD used for movement has either been changed or removed completely from Mass Effect 2. While not game breaking, it IS extremely annoying. And, as a final thought: get rid of the planet scanning mini game. How did that get through play testing?