Droid Google Play Achievements in Cell to Singularity

[pamiproject]

Hello. I've been trying really hard to find out the one achievement that's still locked for my Cell to Singularity progress in Google Play. I finally found the full list on this website, but it seems the one that I'm missing is impossible to figure out the trigger for:

Welcome Achievement - Cell to Singularity: Evolution

Welcome to the game

www.exophase.com

I haven't an inkling of what I should do to get it. Does anybody know?