Defiance is weird, on one hand, it could be a Borderlands MMO easily if you changed a few things here and there and nobody would notice, on the other hand, this game based on some SyFy channel show needs to rethink it's priorities if it wants to be a little better, and also clean up some clunkiness in the interface and how some systems work. That being said, comparing it to a Borderlands MMO is high praise, since I really like Borderlands, and I really enjoyed Defiance.
Set in a post-apocalyptic world, you play an artifact hunter equipped with a computer device that relays you messages from an AI lady and various characters you might or might not care about. You go around, fighting bandits and mutants, weird ant-like aliens, dudes with shields, aliens and big raid bosses. You're outfitted with a trusty shield (with a capacity, recharge speed and recharge delay), grenades with various effects and an array of different gun types with rarities from grey to purple. Gear can also have elements attached to it, like fire or corrosion. You complete missions and Arkfalls (Like the rifts in Rift), drive around to find challenges and side-quests to gain experience and unlock new passive skills to complement the one active skill you chose at the beginning. If this sounds a bit like Borderlands, it's because it does. Maybe a bit too much? Ark hunters, really? The same stats on the shields? Bandits and ant creatures? They could have changed it up a little.
The shooting feels good. You have an array of various gun types and they all behave slightly differently. You can level gun types as you use them, giving your character more proficiency with these weapons and I guess it's tough to focus on one gun when you always pick up new ones all the time, this solves itself when you've tried most of everything. Besides bonus effects on rarer guns, there's not much of a grind in Defiance, if you pick up a neat pistol at the beginning of the game, it might last you a while. Guns have trade-offs, maybe one shotgun is stronger but less accurate and you need to reload each bullet separately, maybe this machine gun fires in 3-shot bursts, this BMG might not heal yourself as much, this grenade launcher might fire shots you need to remotely detonate... There's plenty of variety in guns, there's a healing/damaging beam gun that recharges its ammo, there's a gun that shoots headcrabs at enemies, homing rockets, snipers (with very precise scopes) explosive shotguns... And you have a bunch of elements too, my favorite one is Syphon, as it deals massive damage and heals your shields/life.
You can upgrade your weapons by attaching things to them and if they don't have slots you can always add slots by using the salvage matrix and this costs some resources, takes some time, and you won't know what slot gets added because it's random (there are four slots, stock, barrel, sight and magazine). It gets a bit boring when you want to break down items for resources because you need to click about 4 times just to destroy one item, let me check all the items I want to destroy then click 'salvage all' or something.
Grenades and skills are on cooldowns and there are a bunch of shields and grenades depending on what you want. I mostly go for the incendiary grenades and the shields with high capacity and low recharge rate (because I recharge them myself with the healing gun)
And here's my biggest annoyance with Defiance; The loadout system. Basically, you can have 5 different 'sets' of weapons, grenades, shields, vehicles and skills. This could be useful if you have multiple weapons you want to use but usually I'll stick to the same two, same thing for shields, grenades and skills, I have one set that I like and I'm not going to carry 5 different grenades for no reasons, but if you have empty slots in a loadout, it's going to be filled by new things you pick up, if you change your gear in your main loadout, it's not going to change the others, and you can't sell/breakdown to resources/upgrade anything equipped, so you need to go to each loadout and manually equip the same thing everywhere before you can do anything. This is really annoying and breaks the action a little, I wish you could just disable them and only have a primary set of gear. Heavens forbid you switch to another loadout to change your equipment and forget to switch back because you won't have any skill equipped and that's also pretty annoying.
After a little tutorial where all skills are more-or-less explained, you have to pick up between automatically reloading your gun and dealing more damage, creating a decoy, moving faster or shielding yourself with invisibility. Then when you get EGO points you can spend them to unlock or improve skills around the ones you have, this gets a bit confusing because you won't know what the skills nearby do before you read all of them, so I took the reload + bonus gun damage skill and the skills around are focused on reloading faster, getting more ammo and bonuses to explosive damage. Maybe I would've took something else if I'd knew beforehand. You can get pretty much anywhere you want, but it'll take a bit of time. The skills change the way you play your character in significant ways, my stowed gun reloads automatically over time, I have more life, I get more gear when I kill enemies with explosions, etc. Unlike other skills, this one makes me go close and personal to enemies and reload automatically to keep killing them.
Whenever you go down, you have a self-revive (on a cooldown) or you can pay some money to be resurrected someplace nearby, I would like for the enemies to show in some way if they're too tough for just my character to handle, so I wouldn't run head-on with killer aliens that I can't really do much against. You can also be revived by other players.
Most of the time, on your map, you'll see Arkfall icons, meaning that you have to take your vehicle (you get one doing the main missions and you can buy better ones over time) and boost your way over there for some random encounter with a bunch of other players against predetermined enemies. Vehicles handle well, you can boost (like in Borderlands) to get to places fast, and they level up the more you use them. Vehicles are very fragile and it's a bit weird, you can kill enemies by running them over but it takes a huge chunk of your (immediately respawnable) car's life, that's weird.
When you get to the Arkfall, there's usually a huge crystal, sometimes you have to destroy it, sometimes it's waves after waves of raiders, mutants, bugs, aliens or what not. It gets challenging and pretty insane with all players running around and shooting things, but there are no 'roles' in Defiance, everyone is a DPS, even if you wield the healing guns. After you've won you get some keys (to open chests full of rare loot), a bunch of experience and you can see how you fared in the leaderboards. Driving around, you'll see a couple of challenge types, having you kill enemies using specific weapons in a specific time period to score points, netting you more stuff if you beat a certain score, they're okay.
There's also a huge list of goals to accomplish and they unlock codex entries and give you more EGO rating, reminds me a bit of badass ranks in Borderlands 2...
My second biggest issue with Defiance is how bland 75% of the content is. You get cutscenes and dialogue for the main questlines but everything else re-uses the same two or three lines of text. I'm pretty bummed to hear 'We need to stockpile the materials' five times in a row when I'm on a fetch quest to gather five things. Or 'The hellbugs have found us!!!' on a protect mission. There are a bunch of non-story specific quests in Defiance and they have no flavor at all, you're not even sure if you already went to the spot in question to do a similar quest beforehand, while story missions bring you in different environments, the most common ones will have you drive 200m, kill five guys, loot a thing, then come back, at least if it had some specific lines of dialogue for what you were doing, it would be more bearable. Even the quest givers always say the same thing, the military dude will talk about how this quest is outside the earth republic's jurisdiction and comment on how ark hunters are ballsy and stupid when you complete them. Mix it up a little, make him tell me how this farm is important because of the wheat it produces, I don't know, don't cheap out on the content that pads most of this game.
I liked Defiance, I still like it! I might play a bunch more of it to see if there's anything resembling an endgame and try weirder, unconventional weapons. I like the one that shoots headcrabs, the damage is pretty unreliable but they run around and hit enemies.