Here is the full list of all 19 Seasons Beatings achievements.
Acquire 3 snowflakes and unlock the first level set.
Acquire 6 snowflakes and unlock the wrench weapon.
Acquire 9 snowflakes and unlock the second level set.
Acquire 12 snowflakes and unlock the slowmo cheat.
Acquire 15 snowflakes and unlock the third level set.
Acquire 18 snowflakes and unlock the melee weapons only cheat.
Acquire 21 snowflakes and unlock the tommy gun weapon.
Acquire 24 snowflakes and unlock the fourth level set.
Acquire 30 snowflakes and unlock the fast forward cheat.
Acquire 35 snowflakes and unlock the fifth level set.
Acquire 40 snowflakes and unlock the reversed weapons cheat.
Acquire 45 snowflakes and unlock the katana weapon.
Acquire 50 snowflakes and unlock the "Mark Pan" time cheat.
Acquire 54 snowflakes and unlock the final level set.
Acquire 60 snowflakes and unlock the guns only cheat.
Acquire 66 snowflakes and unlock the silenced pistol weapon.
Acquire 72 snowflakes and unlock the MEGACOLD time cheat.
Acquire 80 snowflakes and unlock the random weapons cheat.
Acquire 84 snowflakes and unlock mirror mode.