There are three customizable parts for each rauser: weapons, bodies and engines. On the development side, Vlambeer is trying out some of these lethal combinations, and shares its experience with three parts on its dev blog. The cannon is "insanely hard to use at the start," Vlambeer concedes, but if you do manage to hit something it explodes into shrapnel that blows up whatever it hits; it's particularly effective on boats.
The melee body part offers "something like" negative 80 percent health, but you don't take damage from colliding with enemies. This is doubly helpful as it's possible to melee boats in Luftrausers. The "gungine" is a machine gun mounted on a standard jet-propulsion engine, and that's all the description we need.
Each combination of parts will have its own name, and there will be at least five different parts for each section, meaning a minimum of 125 different combinations. For example, the aquatic propulsion engine and heavy armor body on a standard rauser may be called the "Blastoise," Vlambeer suggests. The soundtrack will change with each altered spec as well, meaning "Different weapon? Different bassline. Something like that. Hell yeah. Kozilek is gonna be busy."