Engine Parts are your weapons, modifiers and connection tools. The safest way to evaluate a new part is by asking what role it fills, how much grid space it consumes and what it needs beside it.
Adaptive parts
The tutorial describes Adaptive Parts as the main weapons of the ship. Examples seen in demo footage include Long Cannon, Laser, Missile Launcher, Turret, Orbiter and Repulsor.
Fields and modifiers
Fields can increase stats for everything under their area of influence, making efficient overlap valuable.
Extensions
Extensions weld to another part through a connector and can modify weapon speed, ship movement or other attributes.
Network pieces
Connected parts can act as a single unit and gain power from network structure. Poor placement can leave parts inactive.
Scrap and upgrades
Runs produce scrap and other progression resources. Demo footage shows scrap being used to improve weapons during a dive, while Hangar research handles persistent unlocks.