20 is really a lot... I hope the game really is worth that much. Also if it is released cheaper on steam, more like 5-7 dollars, you might attract a larger crowd to play the game as not everybody wants to spend lots of money on games. It looks really cool though. I always thought ant games looked cool, but i have never come across something named other than "ANT SIMULATION GAME SIMULATOR PLAY NOW ANTS!" Looks cool.
It is cool! 20 is a lot for an early access title, but I think it's worth it! If you can wait a couple of weeks, you might get lucky and get it a little bit cheaper in a sale AND have any game-breaking bugs taken care of already! I couldn't wait though and I don't regret it. Unfortunately, even good ant games aren't as popular as they deserve to be, so I'm happy to support (with money) those developers who are brave enough to do it anyways AND do it right.
There was a kickstarter 2 years ago with a really impressive looking game (Formicarium - http://220.127.116.11/formicarium/) but it wasn't successful and the developer stopped working on it. It broke my heart.