A common theme that's going to run through list of suggestions is regression, which is something I've not really advocated before.
The Original did Some Things Right
The first example of where I feel there needs to be regression is in the leveling system. If you're not familiar, in the first Strike Force Kitty game, the fish that you collect on your way through the levels would count toward reaching the next level. In the second game, you can instead spend them directly on attributes via a new training system.
I liked the character of the newer system - the first time I saw it. And then it became annoying. The first game was streamlined in a way that has been lost, and this is something I'd like to see return in a third game, albeit with a small compromise.
The idea of being able to spend points wherever you like rather than 3 each per kitten each level is a good one. So what I propose is bringing back the old leveling system, but instead of awarding three points per kitten, award a pool for the entire party of 12 points, and let the player decide how many go to which character.
I want to see less of a compromise with the combat system. Unless they're going to add active combat skills (which wouldn't really gel brilliantly with a running game), there's no reason to enter a small instance and reduce attack speed with action bars. I thought that the simple combat of the first game was much less jarring than the approach taken in the second, and it slowed me down less, too.
I mentioned in both reviews that Strike Force Kitty 1 and 2 need a fast forward button. This, for me, is a no-brainer. There's nothing that will annoy players quicker than recognising when a game doesn't respect their time. Sadly, I felt that Strike Force Kitty 2 added even more aspects that got in the way of enjoying the content, and the new battles in particular would have benefited from being able to speed them up.
More Flexible Customisation
If there's one thing I love about this series, it's the ability to dress up your team of highly trained feline combatants. It's a shame then that the design of the game works against this - I always preferred some costumes over others and yet the costume that I wanted to put on one of my brigade might not have the ability that they need - so there's always this internal conflict between form and function.
I'd like to be able to assign abilities to costumes. Unlocking abilities can still rely on completing sets, but instead of them being tied to the new costume, I'd like to see them appear separately in your inventory, allowing them to be equipped to a complete costume.
More Player Choice
My next suggestion is for there to be some way to reallocate the profits of grinding. Rather than having to kill the same fox over and over and over and over to unlock that last piece of a costume, I'd like to be able to spend fish that I've collected on missing costume pieces. This would force the player to choose whether fish should be assigned to leveling up or unlocking, which would make me more engaged in the evolution of my characters.
More customisation in a game that's already based on customisation might seem superfluous, but I encountered several comments from players who expressed frustration at not being able to tweak the basic, undressed appearance of their strike force. They could include templates of various cats - longhaired, siamese, imitation Tiger and so on. Another addition that could be considered is different voices - give them attack grunts and different meows to make when they're defeated.
That about covers it for improvements that I'd like see in a third Strike Force Kitty instalment. The series, despite my generally unfavourable summaries, isn't far off being really good - I just find that they hamper me too often for me to hold a sustained interest. I can't help but feel next time it will either be purrfect or catastrophic.