Progression is slow, and will be slower if you don't pick the "right" upgrades. Auto miners are slow and not really worth it at the start, while auto collectors are underwhelming, so either you play actively or it's gonna take even longer. Review is positive because I did have a good time playing, but only because I invested on asteroids quickly and played actively through it. Otherwise I would've gotten sick of it really fast. I don't think the rest of the comments are being fair on it, though, so try it for yourself and see. It's free and takes less than an hour to end, if I remember correctly (I did play this a few days ago)