Overview
A guide on how to unlock Loader by doing the challenge guidance offline
The eggs
There are a couple of eggs in nests scattered around Siren’s Call. To get there easier you can use newt altar for 1 lunar coin and go to the bazaar and hope that Siren’s Call is one of the dreams.
Once there destroy 4 of these and you should see a message about a distant whirring, while smashing number 5 will tell you that the distant whirring is louder and a boss will spawn in. Defeat the boss and you unlock Loader.
The end
Thats all I know, no idea if the boss is hard cuz I just 2 shot him with Preon Accumulator and a fuel cell on easy.