Overview:
-Estimated achievement difficulty:
3/10
-Offline
41/41 [1000/1000]
-Online
None
-Approximate amount of time to 1000
10-15 hours
-Minimum number of playthroughs needed
1 (level replays needed though
-Number of missable achievements
A few, but you can replay levels
-Do cheat codes disable achievements?
No Cheats
-Does difficulty affect achievements?
No
-Glitchy achievements
None
-Unobtainable achievements
None
-Extra equipment needed?
No
This is a fairly straight forward 1000k, you may need to grind a few but follow the guides, and you will have the full score in no time.
Walkthrough
You will unlock 9 achievements for 130

just from playing through the story. It doesn't matter what difficulty you chose for this as there are no difficulty related achievements. However you will get many achievements on the way to this.
Follow
this guide to make sure you collect all of the gene upgrades and secret as you will need them all to unlock
X-Files, Snoop, Post Graduate and
Batchelor. The gene upgrades unlock different skills for you to use throughout the game. Make sure you are using these skills throughout the game to maximise your achievements.
Your character will get stronger throughout the game. Make sure you are using all of your abilities and the following achievements will be awarded as you play through.
Master Of Reflection - Simply deflect 200 shots over the course of the game.
Butcher, Bloodbath - Kill 5 & 8 enemies with Rage. Level 8 is the best place for these
Overmind - Take 30 enemies under your control.
Cat's Eye - Spend 15 minutes in alien view. Use this whenever you can as it takes a while to accumulate all 15 minutes
Illusionist - Kill an enemy with a reflected shot. You will get this soon after you get the ability.
There are a lot of kill x with x type achievements, but most of these will come naturally throughout the game, things like close combat kills, grenade kills etc. You should have most of these by the time you have finished playing through. Be sure to shoot any bottles and barrels you see for
Anonymous Alcoholic and
Explosives Expert.
You can unlock
Collector on the first level by picking up all 4 melee weapons, however these weapons are pretty useless as guns and ammo are everywhere in this game.
On the second level where you are being chased by the beast do not kill any human enemies for
Humanitarian, but remember you can replay any level so don't worry if you don't get this first try.
When you fight the Terminator on level 5, kill him with a grenade instead of performing a fatality to unlock
Ripper.
On level 6 you will fight the Annihilator, again kill this sucker with a grenade for
Energy Blast. Beware it is quite easy to kill him accidentally before you get the chance to throw a grenade, just take your time when his health gets pretty low.
On the final boss level, you have to kill him in a few different ways. Once you have one you can just reload the last level and kill him the other way. Kill him with his own shot, reflected by your shield for
Suicide, kill him with a grenade for
Deadly Metal and use Isolation to kill him with an alien for
Alien DNA.
Once you have finished your playthrough there is a little method you can use to get
Immortal. This is awarded for completing all levels without dying. As it says, complete all levels, not complete a playthrough. Load up a level, and play through to the final checkpoint. It doesn't matter how many times you die, but when you get past the checkpoint, exit the game to the dashboard. Go back into the game and select Continue Game, and it will start you at the last checkpoint with 0 deaths. Finish each level from this point without dying and this will unlock.
Mop Up
There may be a few miscellaneous achievements that you don't have by now, so simply replay a few levels to mop up any kills, barrels, fatalities or even maybe jumps you need.
Conclusion
This is an easy 1000

but do not expect to be playing a great game. It has some cool features but the graphics made my eyes bleed, and even though it was a pretty quick completion it felt like it took a lot longer than it did. It is not the worst game around but won't win any awards. The achievements are all pretty straightforward and using the method to complete all levels without dying will save you a bunch of time.