Fossilfuel

Fossilfuel is a survival horror game set in Sierra, a massive underground research facility beneath Great Sitkin Island in Alaska. Genetic researchers have bred mutant dinosaurs, and the facility is invaded by special forces seeking to steal their DNA. Trapped inside, you use clues and solve puzzles to escape, while fighting soldiers and dinosaurs with an arsenal of conventional and science-fiction weapons.

Sierra and the island

The game includes several large maps that you can approach in different ways. Your decisions determine the ending. After escaping the depths of Sierra, you face the sprawling landscape of Great Sitkin Island. The main story takes around 6 to 10 hours, depending on your skill.

Enemies and combat

Soldiers communicate with one another, call for reinforcements and radio ahead to prepare their comrades elsewhere on the map. They provide covering fire, flank you, notice dead soldiers and listen for sounds you make; they can even spot you turning on your flashlight. You can fight back with shotguns, rifles and science-fiction weapons, including a black hole gun and weapons that warp physics and crush enemies' bones.

Dinosaurs also hunt you. Velociraptors have strong eyesight and can hear your movements. They often travel in pairs and flank you, while the game's other dinosaur enemies are left undisclosed. Enemy AI can make soldiers flank and call for reinforcements as circumstances change.

Ranks and achievements

The game tracks your time and experience and awards a rank at the end. Higher rankings are tied to achievements. Fossilfuel's rank thresholds are:

• Rank S: finish in under 1 hour with over 500 XP.
• Rank A: finish in under 2 hours.
• Rank B: finish in under 3 hours.
• Rank C: finish in under 4 hours.
• Rank D: finish in over 4 hours.

A separate demo has its own rank thresholds, but no achievements:

• Rank S: finish in under 15 minutes with over 75 XP.
• Rank A: finish in under 20 minutes.
• Rank B: finish in under 30 minutes.
• Rank C: finish in under 60 minutes.
• Rank D: finish in over 60 minutes.