Really cool! It took me a while to understand what I was trying to do, but eventually I got that you step on the ink to get the effects, and it opened things up for me. Once I got into it, I was hooked; it's a very fun and frantic gameplay loop, constantly moving and avoiding your own trail along with the enemies.
Usually in games like this, I hate the melee weapons, but you've added enough range and AoE (at least to the sword) to make them almost competitive with the ranged options. I ended up going for the Uzi type weapon, but it was a close call between it and the sword! (E.g. sword over the flintlock thing any day of the week.)
Overall, everything felt really polished and the gameplay is fun. Excellent work on this!