Sentinel 3: Homeworld Guide (Mechanics & Tactics)

Hidden game mechanics, winning strategies and tower setups

Gameplay Mechanics & Useful Info

Sentinel Stats

• Commander Strength is useful for Campaign mode, but useless during Endless mode.
  
• Health and Strength are obsolete after around wave 150 and risk being one-shot at higher levels.
  
• [Artemis (1st Campaign)] Morale increases the power and radius of Artemis' aura which buffs all towers within its range. Max Morale is optimal for Endless mode.
  
• [Aurora (2nd Campaign)] Psi affects aura size and ability damage. Enemies that are killed within its radius will be converted to a small amount of Energy (recharges Sentinel Weapons).

Interest Bonus

• Interest Bonus is always 5% of the money in your bank at the end of a wave.
  
• It may be more effective to hold off on buying harvest drones until around wave 25 or 30, in order to accumulate money from interest bonus which can be crucial for buying initial towers. On the other hand, if you feel that a lot of waves will last longer than usual, then buying a couple worker drones and a production drone right away can be beneficial.
  
  • Maps with less than 60 waves usually don't require any drones.
• Missiles (Sentinel Weapon) can come in handy early on when enemies are attacking your barrier because you're saving as much money as you can to take advantage of Interest Bonus.

Experience and Mob Kills

• [Artemis XP (Campaign 1)] 18. Biomass (Psycho or Hard difficulty) is the best map for Artemis Experience (~2,500 XP per hour).
  
• [Aurora XP (Endless 2)] 1. Frontier (Hard) is the best map for Aurora Experience only if you can survive to at least Wave 200 (~1,200 XP/hr).
  
  • Campaign 2 maps give around 600 XP/hr, with the best being 1. Dark Side (Psycho) at 850 XP/hr.
• [Mob kills / Alien Extinction achievement] 1. Outpost (Endless 1/ Easy) gives ~160 kills per minute if you stop at Wave 100.
  
  • Note: While this achievement is time consuming, it seems like more credit is given for what you actually kill (i.e. 1 kill is actually recorded as 1.25 kills). This needs confirmation though.
• XP bonus for Endless maps increases exponentially, especially noticeable after wave 200
  (1k+ XP every 15 waves on Hard and Psycho).

Misc.

• Classic mode yields no Credits or Experience.

Armory (Weapons / Turrets)

Ground Units

Laser
A basic turret that can shoot both air & ground enemies.
Max upgrade: Power Shot
Damage: 1 / 2 / 4 / 15
Cost: 20 / 20 / 20 / 60

Bomb
Launches explosive bombs at ground enemies.
Max upgrade: Cluster bomb
Damage: 16 / 45 / 80 / 200
Cost: 50 / 50 / 50 / 150

Slow
Releases a sonic boom which slows all ground enemies within its range.
Max upgrade: Triple boom
Damage: 20 / 25 / 30 / 35
Cost: 60 / 50 / 50 / 100

Beam
Unleashes an ultra powered laser at an air or ground enemy, dealing huge damage.
Max upgrade: Multi-Beam
Damage: 300 / 900 / 1400 / 1800
Cost: 200 / 250 / 250 / 600

Sniper
A high power turret which can shoot air & ground enemies from long range.
Max upgrade: Fast reload
Damage: 300 / 700 / 1100 / 1800
Cost: 250 / 300 / 300 / 500

Missile
Missile battery unit launches homing missiles at flying enemies.
Max upgrade: Six shooter
Damage: 35 / 100 / 220 / 900
Cost: 50 / 60 / 80 / 300

Line Laser
High powered beam laser fires in straight lines at ground & air enemies.
Max upgrade: Power beam
Damage: 8 / 25 / 50 / 150
Cost: 100 / 120 / 120 / 400

Flamethrower
Shoots high temperature jets of fire at ground & air enemies.
Max upgrade: Chemical flame
Damage: 3 / 20 / 40 / 65
Cost: 80 / 160 / 160 / 500

Aerial Slow
Fires plasma spheres at aerial targets to slow their movement.
Max upgrade: Six shooter
Damage: 20 / 30 / 35 / 40
Cost: 40 / 50 / 60 / 180

Booster
Increases the damage, range and firing speed of nearby turrets.
Max upgrade: Super Boost
Damage: 5 / 15 / 30 / 60
Cost: 100 / 200 / 300 / 500

Disease
Infects an enemy with a disease which damages and spreads to nearby foes.
Max upgrade: Long Infect
Damage: 5 / 25 / 50 / 80
Cost: 70 / 150 / 200 / 450

Artillery
Fires a deadly explosive shell from a huge range at ground enemies.
Max upgrade: Napalm Bomb
Damage: 30 / 100 / 220 / 300
Cost: 100 / 150 / 150 / 500

Sentinel Weapons

Note: Ion Bomb, Slow Beam, Orbital Laser, and Vortex are all 'Manual' Sentinel Weapons, which means you aim them yourself by clicking and dragging the weapon's crosshairs around the field to target enemies.

Missiles
Deadly homing missiles that target any air & ground enemies in the area.
Energy Units: 2
Duration: 20 seconds

Attack Drones
Releases a set of drones that home in to surround enemies and attack with short range lasers.
Energy Units: 6
Duration: 50 seconds

Napalm
Sweep the whole area with devastating chemical streams of fire
Energy Units: 4
Duration: 3 seconds

Ion Bomb
Drops a laser-cage bomb that causes damage over time to any enemies that pass through it.
Energy Units: 10
Duration: 60 seconds

Repair Beam
The Sentinel can use energy reserves to recharge and rebuild damaged barrier structures.
Energy Units: 7
Duration: 30 seconds

Slow Beam
A targetable plasma beam that slows air & ground enemies within its path.
Energy Units: 8
Duration: 60 seconds

Resurrection
Uses energy to instantly return the commander to battlefield.
Energy Units: 3
Duration: 0 seconds

Orbital Laser
Using the maximum energy reserves of the Sentinel, a targetable laser that delivers certain death.
Energy Units: 12
Duration: 30 seconds

Vortex
A targetable vortex that can warp enemies back to the start of their path.
Energy Units: 9
Duration: 12 seconds

Turret Energizer
Supercharges all turrets increasing their damage while this ship weapon is active.
Energy Units: 10
Duration: 50 seconds

Tactics (Recommended Weapons)

Ground Units

Artillery
Disease
Flamethrower
Missile
Beam
Sniper
Slow
Aerial Slow

• Artillery - (splash dmg.) Max upgrade creates an explosion that sets the ground on fire which deals massive damage to enemies that walk through it, and remains on the field until the weapon's next projectile makes its deadly impact. Hard maps require about 8 of these, and 12 for Psycho.
  
• Disease - (splash dmg.) Heavy, fast acting, damage over time. Spread 2 or 3 of these out for any given map.
  
• Flamethrower - (single target) - Decent damage and also applies a DoT (damage-over-time). Place about 5-10 of these so that enemies are taking 50-100% constant damage throughout the map
  
• Missile - (single/multi-target) Targets flying enemies. Max upgrade targets six flying enemies. You'll need about 10 of these on a Hard map and 15 for Psycho.
  
• Beam - (single/multi-target) Highest damage tower. Max upgrade targets 3 enemies at increased rate of fire. Try to place about 10 or 15 give or take.
  
• Sniper - (single target) - Highest damage tower (same as beam) and largest radius. Max upgrade doubles the rate of fire. These boss killers should take up all remaining spots on the map. Bosses have about 1,000,000 health each around Wave 150, on Hard difficulty, just to give some perspective.
  
• Slow - (multi-target) - Must have. Place so enemies are constantly slowed.
  
• Aerial Slow - (multi-target) - Must have. Place so enemies are always slowed.

Sentinel Weapons

Missiles
Orbital Laser
Vortex
Turret Energizer
Repair Beam
Resurrection

• Missiles - Good for early waves when accumulating interest bonus, or if enemies are attacking a barrier.
  
• Orbital Laser - Insta-kills anything it touches. Long lasting, player-controlled, draggable crosshairs. Nukes bosses.
  
• Vortex - Must have for bosses. Sends enemies back to the beginning of the track.
  
• Turret Energizer - Effective for the most part, but requires maximum energy to use.
  
• Repair Beam - Powerful heal for barrier damage.
  
• Resurrection - Revives your fallen Sentinel.

Example Setups

Endless 1 / 1. Outpost / Easy / (Lv.20 Aurora)

Endless 2 / 1. Frontier / Hard

Endless 1 / 8. Winder / Easy

Note: Booster was loaded in a Ground Unit slot instead of Flamethrower, and Ion Bomb was loaded in a Sentinel Weapon slot instead of Missiles.

Enemies

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Levels (Maps)

Campaign 1

1. Touchdown
   
2. Arachnids
   
3. Split Defense
   
4. Canyon Run
   
5. Death from Above
   
6. Convergence
   
7. Power Up
   
8. Bunker
   
9. The Warrior
   
10. Hellfire
    
11. Mountain
    
12. The Oven
    
13. Counter Attack
    
14. Fortification
    
15. Channel
    
16. Re-Counter
    
17. The Swarm
    
18. Biomass
    
19. Sniper Nests
    
20. Final Fight

Campaign 2

1. Dark Side
   
2. New Hive
   
3. Amphibious
   
4. Bio Weapons
   
5. Incubator
   
6. Backdoor
   
7. Teleporter
   
8. Canal Crossing
   
9. Air Raid
   
10. Bombardment
    
11. Insurgence
    
12. Queens
    
13. Behemoth
    
14. The Pit
    
15. Last Stand

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Endless 1

1. Outpost
   
2. Junction
   
3. Meander
   
4. Intersection
   
5. Pitchfork
   
6. Shunt
   
7. Spiral
   
8. Winder
   
9. S Bend
   
10. Death Alley
    
11. Triangle
    
12. The Cave
    
13. Clifftops
    
14. Ravine

Endless 2

1. Frontier
   
2. Gully
   
3. Bypass
   
4. Double Weave
   
5. Hatchery
   
6. Ridge
   
7. Up and Down
   
8. Overflow
   
9. Omega Gorge
   
10. Valley
    
11. Reclamation
    
12. Swerve
    
13. Undulation
    
14. Crater
    
15. Fortress

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Classic 1

1. Classic Outpost
   
2. Classic Meander
   
3. Classic S Bend
   
4. Classic Triangle
   
5. Classic Cave
   
6. Classic Ravine

Classic 2

1. Classic Gully
   
2. Classic Double Weave
   
3. Classic Ridge
   
4. Classic Valley
   
5. Classic Reclamation
   
6. Classic Fortress

Collected Data

[ToastyWombat]

So if the booster tower buffs range, attack speed, and damage what is the cutoff for it being worth building a booster versus building an extra beam/sniper turret?

[NibKing]

@Arcane Azmadi Thank you - updated

[Arcane Azmadi]

Strange, I thought I'd mentioned here before: maxed out Beam tower actually targets 3 enemies at once, not 2.

[Partenope]

very well done, thank you