Fracture

Genetic Research Base:
Come to an large enclosed area with a Dragon's Breath turret and tons of enemies. Don't bother fighting them. Use cover and then crates to make your way towards the exit 2 floors above you. Moving towards it will trigger an enemy to open the door. All you have to do is get through that door. The only enemy I killed was the guy who came through the door, and if you sprint maybe you don't even have to kill him.
In the next area, you don't have to bother with the Creepers. Pipes on the right side of the map will get you most of the way to the 1st generator. After that, use Terrain Deformation to turn on the "hard light" walkways. Snipe enemies as necessary.
The next major area is after you take the freeze gun and ride an elevator. Use TD to make cover and head to the right to get into the tunnel where you will have far fewer enemies. Walk to the end, take out the turret operator. Use TD to activate a switch. Sprint to the other side to get close enough to use TD to activate the other switch. The hatch in front of and below the turret will open. Sprint over and hop in. There is far more freeze ammo than you can use down there. Kill the enemies guarding the generators. After the generators are destroyed, a hole will be bored behind the turret. Kill a few enemies outside if you feel you need to, but eventually use TD for cover and you ought to be able to sprint out of the generator stairways and to the hole to jump down and face 3 weak enemies.
Kill 2 Cheetahs. Go forward and jump down to kill 2 Cheetahs who are close to you. Then kill Cheetahs that are far away. If you need the Raptor rifle on the edge of the top floor, you can fire a Lodestone round towards the dirt to pull the Creepers above ground. The Cheetahs will stop shooting at you and instead shoot at the Creepers whenever they see them (the Pacificans didn't put enough thought into this whole Creepers-as-defense idea, did they?).
Sprint across the ground and fire a Lodestone round if the Creepers get too troublesome. It will pull them away while you finish getting to the structure.
Most guides tell you to use the platforms to get across the lava and fight the Cheetahs when they appear. Instead, if you edge along the narrow, righthand path towards the wall you have to get over, you can force the Cheetahs to appear, then retreat back to the structure and pick the Cheetahs off from behind cover.
Recon:
Bolla. I hate Bollas. The only non-obvious advice I have is that I managed to get the first one stuck behind the Bulldog ammo case while I stood behind the Raptor ammo case. In other words, I think if you run down the wall on the long side of the area, you might be able to jam the algorithm that makes it walk or even throw things at you because there is something in the way. If this happens, you can shoot into the two front green spots until they turn red, and then you only have the back to worry about. When you go for the back, at some point it will break free and chase you as usual. Also, it's hard to tell how much more damage you need to do because even when the spots have changed color, it will take several more shots to kill it.
The ammo cases sometimes deflect the boulders the Bolla throws, but not reliably. It's helpful, but not guaranteed.
Other than the Bollas, the rest of the Recon chapter is relatively easy. The automatic turret is so effective that all you have to do is watch your shields and retreat when necessary. The biggest problem I had was making the ramps for the harder vehicle jumps.

Just won this achievement - here's a couple suggestions for fighting the bolla based on my experiences:

olde fortran 77's strategy (see above) for the FIRST bolla battle of running back and forth along the one wall with the two weapons crates worked well for a least the first half of the match. I was able to get the bolla "stuck" behind the weapons crates a couple times while trying to get this achievement, but I couldn't do it reliably.

What worked for me was:
- initially get to the wall with the weapon crates. Run back and forth along the that wall refilling your ammo while shooting the bolla. High jump over him when he approaches, obviously.
- NEVER TURN YOUR BACK ON THE BOLLA!! When I did I would die quickly. Move backwards when you have to, but always face the bolla.
- When the bolla throws his balls (bwaa haa haa), if you leap forward when the ball approaches it will likely stop "tracking" you.
- MOST IMPORTANTLY - Use terrain deformation to make a mess of the ground in the arena. I mostly raised the terrain, which while sometimes limiting my visibility, it made the balls the bolla throws roll in an irregular path that is more easily avoidable. It also seemed to reduce the effectiveness bolla's ability to follow me. When I started doing this, I won the battle the second time I tried it.

While there are multiple bolla battles in Act II, the first is by far the most difficult.

Hope that helped. Good luck.