Squids is an interesting way of bringing tactical strategy to a very casual kind of game. The game has a nice RPG layer, with turn-based combat and classes of units that you can train and level up while playing. But the "combat" itself is super casual. During fights you essentially pull back and fling your squids around. In a way it feels like the game combines casual gameplay with more tactical thinking. Unfortunately, in practice the game never really succeeds at either.
Merely seeing how the two styles mix is fun. The game's only 99 cents for the launch sale right now, with full Game Center integration and plenty of content to explore. I'd say look at Squids if you're more looking for something more casual, but if you are really into tactical RPGs, it's likely you'll need a little more than this. On the other hand, if you've heard good things about games like Final Fantasy Tactics or Shining Force but tend to play more casual titles, Squids might be a great entry point. Final Fantasy Tactics is on iOS as well, but it ratchets up the complexity quite a few notches from Squids, even if the gameplay is similar.