not too bad, spent a good 9 hours for full completion - badge-worthy at the least! The grinding wasn't completely unbearable, and the evolution trees were fun to figure out. The graphics were kind of painful at first, but became more bearable after an hour or so, and stay original considering the inspiration (same can't be said of the text, but wasn't bored by it at least)
One great thing in this game is the economics; at the start, a few days of in-game grinding can get you up where you can defeat the next path -- and later on gold becomes nearly worthless, so you can concentrate on completion without MORE needless grinding.
4/5, and hope for a sequel!
after a couple days, when you finish the first planet and find out you need to keep going back for minerals: get down to the fifth layer (greyish), tilt all the way to either side, open a new tab of cat videos, go get a drink, come back 10 min or so later to 20-30k.
Don't mind the badges on an older game; classic is a cinch (if a bit long), and afterwards the pro is a piece of cake... Could use a hard badge due to the time it takes to go through :D