Oh, that is interesting. ( One "good" thing about this is makes it virtually impossible your players could create maps Smiley ) So I guess what happens is I played (and failed each time) until by random coincidence I got a playthrough where randomly all 4 towers were placed near each other.
This does kind of heighten the "there's probably no way to win on purpose" problem, I think, but it's also interesting because it means by random chance some players will probably wind up with VERY interesting structure to their maps and still wind up completing the game.
I tested game with all random tower placings, and all of them are passable
There is a clever way to find all the towers
Of course, sometimes I found the last tower, being neck-deep in water. However, out of 10 attempts, I was drowning only 3-4
This may not be so bad, it may be better than the other option at least (what I do is I keep tweaking things until they're perfect, and that means I never release anything!!)
Yes, it needs happy medium