Super hard! but it's really solid and fun when you get the hang of it. I got an 885 on my first attempt and haven't been able to beat that yet. The art is great, it's very streamlined and fits the vibe the game is going for and feels super cohesive. The music is so chill and well done I feel like I could get lost in the game for hours.
Really smart making it for a phone aspect ratio and I can see this doing really well on the IOS or android market. Very clean all around.