Here is the full list of all 24 RetroRealms: Halloween trophies - there are 10 bronze, 6 silver, 7 gold and 1 platinum.
Collect all 23 Halloween Trophies as Michael Myers
Beat World 1 as Michael Myers
Beat World 2 as Michael Myers
Beat World 3 as Michael Myers
Beat World 4 as Michael Myers
Beat World 5 as Michael Myers
Use Myers' Charge attack 100 times in Halloween in a single game
Pogo off 3 enemies in a row without touching the ground as Michael Myers
Pick up all Jack o' Lanterns
Kill 1,000 humanoids
Defeat yourself by staring into the darkness as Michael Myers
Pogo off 10 enemies in a row without touching the ground as Michael Myers
Clear Halloween Level 3-2 with only special moves bought from the store as Michael Myers!
Clear Halloween Level 4-1 with only sub-weapons as Michael Myers
Use the Bola sub-weapon 50 times in Halloween
Pierce 5 enemies at once with a single Pitch Fork in Halloween
Use one Sickle sub-weapon to kill 10 enemies in Halloween
Complete the game with no health upgrades purchased as Michael Myers
Throw the Hammer sub-weapon 40 times in Halloween
Be active in Halloween for 300 minutes!
Pacifist run through Level 1-1 as Michael Myers
Visit the nightmare realm 300 times as Michael Myers
Beat Mister F in under 45 seconds
Beat Stage 3-1 in under under 1 minutes 45 seconds as Michael Myers