First off, let me say that I was probably one of the few people who would have accepted Mass Effect 2 if nothing but the actual story had changed. While there were some aspects of Mass Effect that weren't perfect, I forgave them easily. That being said, Mass Effect 2 fixes pretty much everything the original's fans complained about.

Visually speaking, Mass Effect 2 feels a lot bigger and more detailed. Not only do we get to see some new races and more detail during conversations, we can also experience a wider variety of locations. Even the extra side mission locations which litter both games come through in more detail this time around. In Mass Effect, when you would land on a non-main story planet and drive up to it's base, you could tell pretty much immediately what the layout of the building would be based on it's outside appearance (there were only three or four variations). In Mass Effect 2, on the other hand, each side mission has a distinct feel and isn't anywhere near as generic.

Sound remains a strong point in Mass Effect 2. Not only is there more dialogue and a bigger cast, but there is a lot more chatter on The Normandy as you walk past crew members. One of my favorite things to do after completing one of the game's missions was to go into Engineering and hear the banter between two of the Engineers, since it was always topical and amusing.

Music also feels just as epic and big as it did in the previous game. When you are in the middle of a battle, it roars to life and keeps you active, but when the fighting goes down, the music casually fades into the game's normal background, peaceful tunes (as opposed to abruptly stopping like a lot of games do).

Mass Effect 2 is still an action RPG like its predecessor. With the exception of how you level up and what skills you can assign points to, the game's core mechanics are the same.

As Shepard, you and The Normandy are attacked by an unknown ship, only to be reawakened two years later after a pro-human clandestine organization known as Cerberus has literally brought you back from the dead. With this rebuilding, you not only get the chance to redesign your character (if you are bringing him/her in from a previous save), but also choose his/her class. This nice little aspect not only keeps players of the previous game feeling like they are continuing the same story, but it also makes it accessible for newcomers to the franchise (especially since the game does a good job telling you anything you might have missed from the first game).

It turns out that human colonies have started disappearing around the fringes of Citidal Space. While all of the buildings are intact, it seems that everyone simply disappeared. Cerberus, and their leader, The Illusive Man (Martin Sheen), are going to use Shepard to find out exactly what is going on and look into its connections with The Reapers. The Illusive Man tasks you with tromping around the galaxy hiring certain individuals who will be major assets in your final mission. While there are a few other missions thrown around here and there for the main story, the main thrust is gathering your team and making them loyal to your cause. Where the last game had you gathering only six characters (most of which at the beginning of the game), Mass Effect 2 will have you building a team of 11 different fighters, each with a wide variety of talents and abilities.

It's actually those talents and abilities that really sets Mass Effect 2 apart from its predecessor. Before, each character had quite a few slots to pour skill points into, and while some of them were weapon affinity skills, a good bit went to other class-specific talents like Overload or Push. This system has been simplified greatly by having classes already training to use specific types of weapons well and simply not allowing certain classes to carry certain weapons (which is a shame because I enjoyed my Assault Rifle, even if my character wasn't always well trained in it). The distribution of skill points has also changed this time around. Instead of letting you apply points to whichever buckets you want, you now only level up a skill when you have enough points to make it to the next level. For instance, before, you could apply a point to a skill, and while it didn't give any big boost to that attribute, it increased some aspect marginally. Now, a skill costs 1 point to get it to the first level, 2 points to get the second level, 3 for the third and 4 for the fourth (where you can "evolve" it by choosing one of two types of specializations). This means that you will often get done leveling up your character with a point here or there hanging around since it doesn't fit in any slot. It took a while for me to get used to this, and while I accepted it, it didn't feel quite as good as the previous game's model.

I've really enjoyed how both Mass Effect games have handled the different difficulty settings. Since the game is very open-world and most of the missions can be handled in any order, the developers at Bioware can't simply make enemies in one mission tougher than another. Instead, the difficulty of each enemy A.I. is actually based on your character's level, and the different settings determine which types of enemies are stronger, weaker or on the same level as you so that they scale up as you do. That being said, it seems like Mass Effect 2 is harder than the first game. I don't know if that's just because I've played through the first one enough times to predict where the enemies will pop up or if the A.I. and stats are actually tougher.

What I do know is that there is a new aspect to Mass Effect 2 that really changes the balance of the whole game, and that's the use of actual ammo instead of weapons that simply overheat when used too much. The benefit of the previous game's overheat "feature" meant that you could basically overcome that problem when you buy advanced enough weapons, but now each weapon has a certain number of shots it can fire before having to reload. There is a lot of ammo laying around, and the actual reload time is minimal, but it is possible to run out of ammo, and that is never fun. I feel like the need to go to ammo-based weapons (even though it doesn't really make sense to me in the context of the story), involves the inclusion of the new Heavy Weapons type of armaments. These are various bigger guns that do everything from launch rockets, lob grenades, fire continuous particle beams and even act as flame throwers. With these new weapons, forcing the user to rely on ammo really helps balance the game, because otherwise, the player would just run through the various rooms tearing everything up without any real consequences. As an interesting side note, these Heavy Weapons actually require different types of ammo than the rest of the equipment; I guess it wouldn't have helped all that much in the balance department if you could just reload it as frequently as everything else.

Besides the leveling up system in Mass Effect 2, another major change is how you upgrade your characters' equipment and armor. First of all, there is no real armor upgrade, not like there was before. Previously, in the middle of a battle, you could pull up your menu and change out your characters' armor, weapons, upgrades and ammo on the fly to handle whatever situation you were in the middle of at the moment. Now, whatever weapons and armor you go into battle with is the kit that you will have on you until you get back to The Normandy. There are some weapons lockers occasionaly for changing out guns, but that's about it. On top of that, the only armor customization you can do is with Shepard him/herself, everything else is governed by the upgrades you research or buy.

Upgrades are applied automatically when you have researched (or bought outright) that upgrade. This can be anything from a percentage increase in tech or biotic damage, to better shields, to more effective weapon upgrades. For the most part, you will run around your missions and something on the ground will prompt you to scan it. Upon doing so, you can research that upgrade back on the ship and then it will be automatically applied to all applicable characters/weapons. The actual researching is a new mechanic that involves you doing a much more detailed version of the mineral mining mechanic found in the previous game. Before, when you landed on a world, you could drive around, and if you found a mineral deposit, you would claim it. Besides gaining experience and money, there was no other point to this tasks. Now, you can travel to every planet in every system and scan it from space. This involves moving a set of crosshairs over the planet painfully slowly (less painfully when you get an upgrade to the scanner, but still slowly), looking for spikes in the mineral readout section of the screen. From here, you launch a probe and collect the minerals. While you could spend endless hours doing this task over and over again in all of the systems, there are a couple of limiting factors. For one, it's tedious and I couldn't find myself doing more than one system at a time. For another, probes and fuel cost credits, so eventually you will have to stop and do some missions in order to earn money. While this was a nice bit of balancing on the developers' side, the chore of doing the probing was still pretty tedious. I'm still not completely sold on this aspect of Mass Effect 2, but at least it is something different and completely optional (provided you don't have a desire to own every upgrade).

Mass Effect 2 does a great job patching up the holes many people complained about in the first game. Not only does it create an experience that is compelling throughout with few tedious elements like the first game's Citadel area (before becoming a Spectre), but the game's story really keeps you entertained from beginning to end, and many of the non-required side missions get you right into the action. Yes, it does introduce the aforementioned mineral mining tedium, but like I said, that isn't really required. Mass Effect 2 is a must-have for anyone who is a fan of open world action RPGs.