There are three different kinds of gems you can obtain and insert into stations. They are obtained from presents (often shown as a "?" in a box on the map). One present is always given after you complete a level (before you begin the next one). Gems are lost when you finish a campaign.

Gems can be picked up and thrown into stations to modify them with (usually) helpful abilities. Inserting a gem into a station with no free gem slots will destroy the existing gem and replace it. Stations can only hold one gem initially. Gaining ranks by rescuing Friends (space-bunnies, space-frogs, etc.) will allow you to permanently upgrade stations to have two slots for gems and allow for interesting combinations.

If you place a gem into a station which already has two gems, the gem that has been there the longest will be replaced.

• Power: A pink gem which generally makes the station better at doing what it does.
  
• Beam: A yellow gem which improves the station, usually involving lasers of some sort.
  
• Metal: A gray gem which modifies the station in interesting ways. The results are generally powerful, but sometimes situational and tricky to use.
  
• Remover: Not really a gem as such, but applying it to a station will retrieve any gems currently inserted, allowing them to be repurposed. It can only be used once. Instead of being obtained from presents, a single Remover may be granted between levels (it looks like a toolbox).

All ships have multiple turrets, which by default rapidly fire low-damage bullets with a small spread.

One-Gem Upgrades

• Power: Improves the firing rate of the turret.
  
• Beam: Turns the turret into a railgun. It fires a very fast projectile which deals heavy damage and pierces enemies, but has to reload after each shot. The turret shows a charge meter and a laser pointer to assist aiming.
  
• Metal: Turns the turret into a ball and chain. Holding Use/Fire will extend the ball, and it can be swung around by rotating the turret. Releasing Use/Fire retracts the ball, though it can still hit targets while returning. It does heavy damage to anything it hits but is unwieldy to use against small enemies.

Two-Gem Upgrades

• Power + Power: Further increases the firing rate and eliminates bullet spread.
  
• Power + Beam: Turns the turret into a rapid-firing laser gun. This does decent damage and is perfectly accurate but does not pierce enemies. The turret turns slower while firing.
  
• Power + Metal: Turns the turret into a guided missile launcher. Once launched, missiles can be controlled by the user as they gradually accelerate. If the missile is flying straight, pressing Use/Fire will boost it very quickly in that direction after a short delay. The missile causes heavy damage in a radius around its impact, but only one missile can be launched at a time.
  
  
• Beam + Beam: Upgrades the railgun to have two barrels. Two shots are fired in quick succession with each trigger press, with a reload between each. Sometimes the turret will glitch and only load/fire one shot.
  
• Beam + Metal: Turns the turret into a ball and chain, but the ball has laser guns on it. Extending the ball with Use/Fire will charge the lasers. When charged, releasing Use/Fire will fire lasers forwards and both sides of the ball. The lasers allow it to cover a larger angle but it may still struggle against quick targets.
  
  
• Metal + Metal: Adds a second ball and chain next to the first. They are controlled simultaneously, but will typically fly apart from each other a little.

The two-gem upgrades are shown here, in order (left-to-right, top-to-bottom) as listed above.

All ships have one engine (duh!), which can be swivelled around the ship (except for the Jelly Roll ship, which swivels with the engine). Use/Fire applies thrust in the direction the engine is facing. It can take some getting used to flying backwards.

One-Gem Upgrades

• Power: Gives a small initial boost in thrust when Use/Fire is pressed. Two boosts are stored, indicated by lights on the engine. They recharge quickly. Tapping Use/Fire will use both boosts rapidly.
  
• Beam: The engine charges a laser when Use/Fire is held. When charged, releasing Use/Fire will fire the laser directly out of the thruster, propelling the ship away as well as dealing heavy damage to anything it hits.
  
• Metal: The engine fires caltrops at a moderate rate when in use. These do not fly very far, but linger in place for a while. When an enemy or projectile touches them, the caltrops deal minor damage and are destroyed.

Two-Gem Upgrades

• Power + Power: The engine now stores four boosts instead of two. They recharge at the same rate.
  
• Power + Beam: Holding Use/Fire charges a laser. Once charged, the laser fires continuously from the engine out to a short distance. The laser also increases thrust while active.
  
• Power + Metal: The engine has the same two-boost system as the Power upgrade, but each time a boost is used, a spread of 5 caltrops is launched from the engine.
  
  
• Beam + Beam: Charges two beams side-by-side when Use/Fire is held instead of one.
  
• Beam + Metal: Charges a single beam when Use/Fire is held. When the beam is fired it also leaves a line of caltrops along its path.
  
  
• Metal + Metal: The engine now regularly fires two caltrops at once while in use.

The two-gem upgrades are shown here, in order (left-to-right, top-to-bottom) as listed above.

The two-gem upgrades are shown here, in order (left-to-right, top-to-bottom) as listed above.

All ships have a shield station. The shield covers an arc of the ship, absorbing projectiles and preventing damage from colliding enemies or walls. By default, it covers a small arc. Using the station allows the shield to be rotated around the ship, but it does not provide protection while being moved.

One-Gem Upgrades

• Power: Increases the arc covered by the shield.
  
• Beam: The shield now reflects projectiles. The angle of reflection depends on how close to the centre of the shield the projectile impacted, as well as the projectile's incident angle. Reflected projectiles can be very deadly to enemies.
  
• Metal: Adds spikes to the shield. Enemies which touch the shield will be damaged. The shield is also no longer deactivated while turning, but turns significantly slower.

Two-Gem Upgrades

• Power + Power: Further increases the arc covered by the shield.
  
• Power + Beam: The shield reflects bullets like the Beam upgrade. Instead of increased size, any reflected projectile is replicated, so outgoing fire is doubled.
  
• Power + Metal: Combines an increased shield size with minor damage to anything the shield touches. Additionally, the three "prongs" which generate the shield also deflect projectiles and objects, even while turning. (Thanks Obvious!)
  
  
• Beam + Beam: The shield size is increased slightly, and reflects enemy projectiles with more force. (needs confirmation)
  
• Beam + Metal: The shield becomes a row of 5 "cells". When a projectile strikes the shield, it spawns a cell attached to it. The added cells spawn additional cells attached to them when struck, allowing the shield to be extended outwards. Cells are destroyed if they strike an enemy, dealing moderate damage to it. They are also destroyed if they touch a wall or after a set time. The shield is also not deactivated while being moved, but turns a little slower.
  
  
• Metal + Metal: Turns the shield into a spiked metal barrier with a larger angle of coverage. This deals moderate damage to anything it touches and is not deactivated while being moved, but it turns significantly slower.

The Yamato Cannon is a large yellow gun which rotates around the ship. Players cannot control its facing direction. When activated, it fires for a short duration, while continuing to rotate, before needing to recharge. Its charge is indicated by the yellow tank that makes up most of its station.

By default the Yamato Cannon fires large energy bolts which deal heavy damage to anything struck, instantly killing weaker enemies.

Interestingly, modifying the gem slots of the Yamato Cannon will instantly recharge it.

One-Gem Upgrades

• Power: Rapidly fires small homing missiles which move slowly and steer towards enemies. Targets are indicated with a large crosshair.
  
• Beam: Fires a continuous laser instead of energy bolts.
  
• Metal: Causes a sawblade to spin around the ship for a short duration. Although short-ranged, the sawblade spins more rapidly than other weapons.

Two-Gem Upgrades

• Power + Power: Fires even more homing missiles.
  
• Power + Beam: Fires small lasers in random directions from a "focus crystal" at a high rate. This can potentially cover a wider angle than other combinations.
  
• Power + Metal: Launches spinning sawblades away from the ship, two at a time. The sawblades move quickly and bounce off walls. This depletes the Yamato's charge very quickly.
  
  
• Beam + Beam: Fires three continuous rotating lasers in a cone from the gun.
  
• Beam + Metal: Spins a large sawblade around the ship as before, however the sawblade moves away from and towards the ship in a periodic motion as it rotates.
  
  
• Metal + Metal: The spinning sawblade extends further from the ship while active, and also has two small sawblades orbiting around it.
  
  The two-gem upgrades are shown here, in order (left-to-right, top-to-bottom) as listed above.
  
  

That's pretty much it. Feel free to provide feedback or additions in your comments, and don't get too angry at your lover/friend/relative/space-pet!

Seriously, that space-pet gets extremely confused when on shields.