A very different opinion from my side: I found it great because there are several visual traps and a winning route that is not intuitive. I really had fun solving all the traps. :)
Had fun at it but remove one star because I had no optimization work necessary. The wrong routes I tried were too far from target to be plausible, so I jumped directly to next route and the first shorter one I tried was the winning one. I was like "oh, it's over?". A bit frustrating somehow. :D