Gunscape

Not too difficult if you set the item respawn rate to 3.0 and leave enemy respawning at 0. This allows you to pick up ammo and health over and over as needed. I frequently retreated to collect more supplies after they respawned.

Enemies don't regain health - even if you die - so as long as you can at least damage some enemies before dying you can whittle them down over time. This applies for bosses as well, making levels 3, 6, and 8 pretty straightforward and simple. Experiment with different weapons to find which ones you like best and always be on the lookout for hidden areas containing powerful weapons.

The game is fairly straightforward but if you'd like a video guide here's part 1 courtesy of Zachary Slobogan.

This only covers most of the first level but his other videos cover the rest of the campaign.

Chapter 1 Test Facility


Chapter 2 Into the Underbelly...


Chapter 3 DOLOS AI


Chapter 4 The Point of No Return...


Chapter 5 Outside, Alone


Chapter 6 A Way In, Or A Way Out


Chapter 7 In the Belly of the Whale..


Chapter 8 DOLOS AI v2.0