The ink is mesmerizing, wonderful job on the visual FX there. This is one of the best games that really tries to incorporate the theme + special object to the best of its ability, huge respect for that :)
I found the gameplay to be pretty alright. I beat every level exclusively using the Plus ink, so I never really interfaced with the Minus ink. It was the perfect length; 9 levels was exactly how much time was needed to showcase the systems before they overstayed their welcome, and then enabling infinite ink on the win screen was a nice cherry on the cake.
Well done :)