This is one of the most polished platforming games I've ever played, period. Everything from the movement speed to the way Nadine's momentum transfers from sliding to jumping feels just the right level of weighty. It's everything I like about games like Mega Man but without the frustrations.
The level design is also top-notch, teaching the player through example while also being full of optional little nooks and crannies to explore. These diversions also give the game a dynamic sense of risk-reward, allowing you to ramp up the difficulty for yourself by taking the more dangerous, albeit treasure-filled, route.
The visuals are well-executed, as well. I'm someone who often feels overwhelmed by action games, so it's nice to see that the visuals have a somewhat understated 16-bit charm to them. The whole game is very 'readable,' and it's easy to take in the information and make your next move accordingly. The overall design is easy on the eyes and the brain.
I look forward to seeing this game's continued development, and can't wait for its release!