These are the Fortnite modes that never returned showing up only once and fading away again afterwards. It's a sign of Epic Games constantly trying new creative things and not every Fortnite experience will stick. Some are limited time events too. Below you can find each of them listed with details on exactly what they were. It's an interesting list if you're a fan joining in or perhaps experienced having missed one of them.
Infinity Gauntlet - Marvel event where a player can become Thanos
The Getaway - Players fight over a jewel
Soaring Solos - Glider usage is adjusted for wacky play
Soaring 50's - Glider usage is adjusted for wacky play in a larger scale
Close Encounters - Jetpacks and shotguns
Score Royale - Collecting points to win the victory
Steady Storm - Dynamic storms come into play
Solo + Blitz Showdown - A contest of champions
Solid Gold 50v50 - Weapons become insanely powerful and of a higher rarity
Final Fight - Smaller teams, try to keep the most players alive
Fly Explosives - Jetpacks and explosives
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