Very nice game: with it's minimalist graphics it's eye pleasing and the colour palette is well chosen.
The controls are comfortable for what they were designed for (phones) and overall it's pretty fun when it lasts.
The only things I would complain about would be the difficulty of the game which is really easy to a point and then it suddenly spikes up - please make it escalate and the shitty "download in the appstore" icons on the bottom which look genuinely ugly and kinda destroy the look. What I would suggest is either completely removing them or just make custom icons with your minimalist style. Very good job on the rest though, keep it up!