I was really struggling until I saw the comment about zooming in on the browser page. Then I was able to see the whole interface and it made much more sense :').
I really liked evolving and gaining the upgrades, especially the tongue. For some reason it got harder for me to push enemies when I got the frog arms... maybe they should be slightly sticky like the tongue but only for one fly? Or maybe the controls were confusing me and I kept going the opposite of the way I wanted.
In any case it was fun to collect frog parts! Good game!