Here is the full list of all 998 Sky Jump achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Bird
Cat
Letter
Number
Symbol
Scorpio
Sagittarius
Taurus
Libra
Aquarius
Virgo
Capricorn
Leo
Aries
Cancer
Pisces
Gemini
Dog
National emblem
Black
Flag
simple person
Community Achievement
Lucky_13
Bavarian Achievement Hunter
https://www.youtube.com/user/IAmPokerpo
@TheKidd1986 and @Lalabama01
Lindseeey
http://steamcommunity.com/id/Lindsey_STOMP
steamcommunity.com/id/lesseffort
steamcommunity.com/id/macnex
Since 2013
[ERN] ░LEGEND░ [P-B]
Lord of the hearts
Famous person
Your teammate