Brotato

To have the Danger 3 difficulty you'll need to beat the game in Danger 2

Danger 3 is pretty much like Danger 2 except that the ennemies do more damage. I dont really have tips but just be patient, i recommend to upgrade HP Regeneration (in pratically all the characters i found it useful) and to be patient

If you found it too hard you can still go in the settings (Options>Gameplay>Accessibility) and reduce health or damage of the ennemies. Hope it helps!