As there is no formal guide (as far as I can tell) I think I'll pitch in and tell you what I've learned so far about the game in terms of competing for that #1 Spot on the Leaderboards (you'd better take notes, dustin).
When you start out, you have the option of choosing any combination of cats that you would like to have. They can be toggled in the bar on the right side of your screen; shaded means not selected, while colored means selected. Then simply click on Survival instead of Adventures.
I highly recommend starting with just Jazz , because Spark and Quasar are not all that good. Jazz is a fast cat, but she is still easy to control. Although Spark is smaller than Jazz and nearly as fast, I still think he's not as good because he is harder to touch and move quickly in a crisis (which is actually because of his size, which at first appears to be an advantage). Spark is alright though, so if you prefer him, then go ahead and use him. Quasar, on the other hand, is very bulky and clumsy. Controlling him is kind of awkward because he is too big, and he's very slow compared to Jazz. The one advantage that you have as a cat is your high speed and high maneuverability, and as Quasar I think you sacrifice that far too much.
I very highly suggest you only start out with one cat, whichever one it may be. This is because in survive mode your score is calculated by (Base Score/Number of Cats at the Start). That means if you start with two cats your score will be cut in half regardless of how long both cats were actually in play. Your base score is divided by 3 when you begin with 3 cats. Starting with multiple cats is hardly worth that kind of penalty since it is hard to focus on both cats at once. In addition, you can earn 'bonus cats' as you play, which practically negates any advantage you get from starting with more cats (more on that later though).
When you start out in survival mode it will just be your cat(s) and the collectables on the map. Those collectables are gems, mice, and stars (these are much rarer than the other two, so one probably won't be on the map when you begin). Collecting any of these will give you points which are added to your score. You can check how many of each you've collected by simply looking at the top right corner of the screen.
With a start of one cat you'll receive 10 points for every gem you get, 80 points for every mouse you catch, and 380 points for every star you snatch. In addition every 20 gems you collect will spawn a new enemy, while every 20 mice you capture will spawn a friendly cat (I've never tested to see what happens if you catch 20 mice when you already have three cats out). Gems are of course the most common and they sit still, which makes them very easy to collect. Mice are always on the map somewhere as well, but they are found in smaller quantities and move away from you. Stars appear only once in a while on the map and last only briefly. As far as I can tell there is no event that triggers a star's appearance. They do seem to appear roughly once every 15-20 seconds though.
In terms of general strategy you should avoid gems nearly all costs. Gems only give a pathetic 10 points, and for every 20 you collect a new opponent appears. It sounds like you're giving up a fair amount of points by avoiding gems, but trust me it's worth it. You only get 200 points for causing a opponent to appear! In comparison, 200 points is only 2.5 mice, and 0.53 stars. This isn't to say you should completely avoid gems; be logical! If you have to pick up 3 or 4 gems to get a star it's worth it. Keep in mind having enemies appear is not necassarily awful, it should just be avoided if you can avoid it. If you have only 3 slow dogs or 1 fast dog and 2 slow dogs you're probably fine, but you should avoid getting anymore if it's possible. Also noteworthy is the fact that enemies can die in pits over time (it is more likely if you lure them, but it is tough to do since the enemies are generally slow and the pits don't last that long).
One other notable point is that tunnels can randomly spawn under you, which instantly eliminates your cat and ends your game if that was the only cat you had in the game. The longer your game lasts, the more likely you are to be killed by a pit suddenly appearing under or directly in front of you. Therefore, you can't afford to be super cautious and avoid all gems. It won't be worth the penalty of missed points (from being unable to catch certain stars and mice) and the lost time.