• Ancient Aliens - If the player has [Zorgun] , [Zorgun] gets three special shots at the end of each magazine instead of one. Alien Engine will also fire [Zorgun] bullets.
• Contrail - If the player has [Shotgrub] or [Mutation] , the engine sprite will change and the flame will turn green, igniting enemies with green fire. Alien Engine also grants flight while held.
• Pilot Wingsman - If the player has [Wingman] , it will fire four rockets at a time.
• Space Best Friend - If the player has [Space Friend] , [Space Friend] 's fire rate increases significantly.
• [Heavy Boots] removes the recoil of the gun, making it much easier to use.
• Using [Explosive Rounds] with this weapon creates a small area of fire, along with the usual explosion.
• [Scattershot] will triple the recoil, pushing the player considerably faster.
• With [Backup Gun] , the gun will also fire an invisible flame backwards, though recoil is not affected.
• With [Flak Bullets] , the gun will rapidly fire small bullets forwards, allowing it to be used as a ranged weapon.
• With [Blank Bullets] , the blank effect will be more common because of the high fire rate, greatly decreasing the chance to get hit.
• With the Contrail synergy, the player may use the Alien Engine as a fast way to get around cover during a fight.

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