Nice concept!

An interesting take on making players work for their trick-or-treat rewards.

As some have mentioned, feedback on the progress a player is making as they're going through the combo would greatly improve the playability of the game. Highlighting characters as players successfully press the buttons or removing them from the string of characters as players progress are just a couple of options. If players press the wrong button it's easy to get mixed up as to where I am in the progress of the chain (do I start over completely or just try and press what would be the next input from the last correct one that I did?)

I'd also recommend just using the input characters for the string of commands rather than the full words "Up", "Left", "Right", and "Down". It's not as big of an issue at first since the input strings are only a few characters long, but it becomes really apparent after unlocking a couple costumes and allowing the input strings to get over 8 inputs that the text starts scaling down to fit everything and it gets a bit fatiguing as a player to run through full words rather than just single characters to represent the inputs.

Some kind of feedback when you press the right direction would go a long way. I liked the different costumes, but it was kind of hard to tell what they were with the game's perspective.

Tons of costumes, surprising difficulty and great music! 

Cool Game