Very nice! And... very hard :-)

I think you've done a really good job here, and there is some cool mechanics you've established. If I were to make one recommendation, it might be to limit the available animals in the levels that don't require them, otherwise it's actually quite easy to satisfy many of the requirements just by placing random animals that are unrelated to the puzzle. For example, no elephants next to each other and no turtle/porcupine sharing rows is easily satisfied just by placing any other random animal. That said, great work on this! Well done.

aaah constraints!

I got through the first four before stopping (the fourth I got more by trial and error than by any definite idea of what the solution was).

Anyway, seemed pretty wholesome :)

Very nice concept/graphics. My only complaint is that besides the mechanic, everything else feels very corporate, depending on polish rather than uniqueness.

Great graphics, especially considering the time constraints. The game leaves a little bit to be desired uniqueness-wise, but man, those graphics! Incredibly fast.

That's pretty fun! Discovering the hidden rules is a great idea, but it's so hard that I wound up not really figuring them out. Instead I would just pick a column of animals that work and repeat them diagonally.

Very solid, polished entry as usual. But hell, stages with hidden rules are nasty. Especially once you're down to two or one wrong row.
Once I finished a screen it'd be great to see the hidden rules to verify I've just been lucky ;)

You do see the rules, on the "You Win!" screen!

Couldn't reverse engineer any of the hidden rules :-/

Talk about overkill and scaling issues. I like the concept and think it would be great, but you need to start off slow and scale up for the users. A simple puzzle at first to get used to the game play and what animals go together.

Argh! It's my Archenemy, a puzzle ;-)
Nice graphics, nice audio, but I don't posses the nerves to discover any secret rules :-/

Fun game, nice polish.

Played through it all. Seemed a bit overwhelming and tricky at first, but eventually I realized that *SPOILER* just building diagonals of all the animals */SPOILER* was usually enough (though not when trying for the fewest clicks). Having more kind of rules and not always having access to all the animals might solve that.

Feels very complete and well polished. Hard!

Very cool game! I think it would be a good game for a smart phone (iPhone/Android). And it looks really well polished!