Here is the full list of all 100 Poly Memory: Cats achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Level 50
Sign 24
Sign 23
Level 49
Sign 22
Level 48
Sign 21
Level 47
Level 46
Sign 20
Level 45
Sign 19
Sign 18
Level 44
Sign 17
Level 43
Level 42
Sign 16
Sign 15
Level 41
Sign 14
Level 40
Sign 13
Level 39
Level 38
Sign 12
Sign 11
Level 37
Level 36
Sign 10
Sign 9
Level 35
Level 34
Sign 8
Level 33
Sign 7
Sign 6
Level 32
Sign 5
Level 31
Sign 4
Level 30
Sign 3
Level 29
Level 28
Sign 2
Level 27
Sign 1
Level 26
Z
Y
Level 25
X
Level 24
Level 23
W
V
Level 22
U
Level 21
T
Level 20
Level 19
S
Level 18
R
Q
Level 17
Level 16
P
Level 15
O
Level 14
N
Level 13
M
L
Level 12
K
Level 11
J
Level 10
Level 9
I
Level 8
H
Level 7
G
Level 6
F
Level 5
E
Level 4
D
Level 3
C
Level 2
B
Level 1
A