What a strange but beautiful game!
I found the controls quite difficult as well as the other feedback. Also, the music volume seemed low. I could hear it fine when I was very close to the inhabited planet. But I couldn't hear the ending song.
I felt sorry for the humans suffering from the lack of oxygen, but I also felt a little funny. How cruel of me...
It was so funny that while they were trying to plant trees on the comet and load a large number of humans on it to return to their home planet, another comet was attracted and hit it and humans became extinct, meow~!