Bosses in Cosmic Starship are not just big health bars: each has a mechanic you must break before damage counts, and attacks that are telegraphed on the field before they land. These are all 9, in campaign order.
General rules
- Red markings on the field show where an attack will land. A boost makes you invulnerable for a moment: use it to cross a beam, not to run along it.
- Most bosses have weak points (pods, pylons, bays, engines). Break them first; the boss bar shows what is protecting it.
- Phases start at fixed shares of hull. Save your ultimate and the Surge for the last phase.
- Bosses drop their own loot, including relics that can be forged into relic warships.
The Gate Leviathan

The Ion Tempest · mission “The Sleeper” · level 13
What it does. It fights in two phases: at half hull it sheds its shell and spills its brood.
How to beat it. Before you push it past half, put your interceptor squads on Intercept so the brood does not reach you. Keep your ultimate for the second phase.
The Iron Colossus

The Shattered Moons · mission “The Iron Colossus” · level 8 · 15,000 hull
What it does. Armoured while its four turret pods live. Its attacks are a spinal lance, a rain of shells and mines; at half hull the lance starts to sweep.
How to beat it. Destroy the four pods first: until they are gone the hull barely takes damage. Watch the red line of the lance and boost across it, never along it.
The Phantom Regent

The Titan Graveyard · mission “The Phantom Regent” · level 18 · 11,000 hull
What it does. It cloaks every ten seconds or so, blinks in to ambush you, fires volleys and spawns decoys that look exactly like it. At half hull the whisper fleet joins.
How to beat it. Stay moving when it vanishes: it reappears where it can hit you. Spread your squads on Attack so they find the real Regent among the decoys.
The Mirror Hydra

The Fracture · mission “The Mirror Hydra” · level 22 · 12,000 hull
What it does. Untouchable while its crystal pylons stand. It splits off reflections at two thirds and one third of its hull, and grows new pylons at half.
How to beat it. Kill the pylons, then burst the Hydra. When new pylons grow, switch back to them at once. Its fan of beams is telegraphed: stand between the lines.
The Void Maw

The Deep Veil · mission “The Void Maw” · level 23 · 18,000 hull
What it does. A living black hole that pulls ships in and devours them to heal. When it is gorged it stops, its armour drops and it takes much more damage.
How to beat it. Keep your distance and your boost ready so you are not pulled in. Hold your heavy damage and your ultimate for the gorged window, then pour everything in.
The Unbound

The Deep Veil · mission “The Unbound” · level 25 · 19,000 hull
What it does. The final boss: three phases at two thirds and one third of its hull, with beams, time distortion, chain lightning, novas and rain, and the battlefield itself collapsing.
How to beat it. Bring your best-upgraded ship and full squads. Learn each phase’s pattern, keep boosts for the nova and fan attacks, and save the Surge for the last phase.
The Brood Carrier

The Ion Tempest · mission “The Brood Carrier” · level 13 · 16,000 hull
What it does. A hive mothership. Four launch bays pour out fighters and keep it armoured until you burn them out. At half hull it empties its reserve brood.
How to beat it. Target the launch bays: each one you burn stops a stream of fighters and weakens the armour. Put lancers on the bays and interceptors on the fighters.
The Twin Wardens

The Shattered Moons · mission “The Twin Wardens” · level 8 · 9,000 hull
What it does. Two linked dreadnoughts. Only one can be hurt at a time, and they swap every few seconds. A fallen twin is rebuilt unless its sibling dies quickly.
How to beat it. Focus whichever twin is vulnerable, and when one falls, finish the other fast, before the rebuild completes.
The World Breaker

The Titan Graveyard · mission “The World Breaker” · level 18 · 16,000 hull
What it does. A clan siege hulk marching on your station. Three engine blocks set its pace, and its cannon charges a shot at the station once in range.
How to beat it. Wreck the engine blocks first to slow it down, then take the hull apart before the cannon reaches the station.