Finally got around to playing this and I have to say, it's a great game!
First of all, the petty criticism! For some reason I found that the second level was the hardest of them all; I still didn't quite get the mechanics and the wording in the briefing is rather confusing. Also, while this may seem intuitive to everyone else, I didn't instantly understand that year 0 was the time most in the past. Also, level 18 seemed to me like I was exploiting rounding errors, which felt odd. You should also explain somewhere that distance influences migration rates. I had no idea!
And in really
minor criticism the music did annoy me, but not too much
I found the loop too short and the notes played too dissonant.
With that out of the way I can only restate that it's a damn good game. At first I did think that the mechanics were poorly thought out but when I wrapped my head around it and started thinking more in the terms of "What must've happened so that from the initial conditions we got to the current ones?" I enjoyed the game to it's fullest and had a great time.