As a long time Copper Cube 6 user, I was very impressed by the design, the gameplay, yet the ending needs to be worked on.
Surprisingly decent game. I liked the atmosphere, felt really tense. The mechanics were simple enough, but different from other games that are in the same genre. Overall, not bad. I highly recommend (more like beg) to have a proper ending screen, rather then closing an application, which shows that the game might have a bad design.
Best of luck with the future games!