Here is the full list of all 100 Petty's Adventure: Desert achievements.
Level 50
z
Z
Level 49
Level 48
y
Level 47
Y
Level 46
X
Level 45
W
Level 44
v
Level 43
V
u
Level 42
Level 41
U
t
Level 40
T
Level 39
Level 38
s
Level 37
S
r
Level 36
Level 35
R
Level 34
q
Level 33
Q
Level 32
p
Level 31
P
Level 30
o
Level 29
O
Level 28
n
Level 27
N
m
Level 26
Level 25
M
Level 24
l
Level 23
L
Level 22
k
Level 21
K
j
Level 20
Level 19
J
Level 18
i
Level 17
I
h
Level 16
Level 15
H
g
Level 14
G
Level 13
Level 12
f
F
Level 11
Level 10
e
E
Level 9
Level 8
d
Level 7
D
Level 6
c
Level 5
C
Level 4
b
Level 3
B
Level 2
a
Level 1
A