This is Stamper/JohnnyUtah level quality, I was in tears when I saw this on youtube. You're extremely talented. Also might want to add RicePirate to the NG credits as voiceactor. Keep doing what you're doing. Astounding quality.

Is this still flash? Feels more like ToonBoom but I could be wrong. What the FUCK. The teeth music box jesus christ. Brilliant new installment to a classic series. The production, the sound, it all did it's justice by me.

That made me way too happy. Very fluent dance graphic you got there. Everything is in sync and tight like a prom queen's puss. Brilliant way to celebrate ClockDay, great work!

Feels as if it belongs in the pixel-art category but none the less, it is an illustration, maybe both ahah.
Decent proportion and all that, maybe work on making the stance a bit less icy and static. Were you going for an MS Paint look? Jussayin, if you weren't, looking into something a bit less sharp and harsh on the res, something with vectors. This work is alright, not at all captivating but in terms of practicing form and drapery, it's a real top effort man, Good job!

Alright, "proper" review time yeah?
Now, I really admire the physique you've given her, like in terms of proportion. I can never get that right, so respect to that. Despite the simplicity, I like how you have an exact light source for the shading, a lot of people, including me, struggle to keep the shading around one specific light source, whether it's seen or unseen in the picture. To be honest, the only quarrel I can well up (which is really just subjective and petty more than anything) is the line thickness, feels a bit too blocky and rounded for a character like Harley Quinn.
Which Batman inspired you to make this by the way? The 'Arkham City' game redesign was horrible! She looked like a young teen trying to live up to her version of "hardcore". There's often a fine line between cheeky looking and the childish/immature portrayal which comes off as making the artist seem a tad creepy. You, my friend, didn't cross that line.
Hope this review proves helpful, thanks man. :)