You are timed in the normal and tricky modes , although not in easy, so the clock counts down.   Should you fail, your kittens will be in a bad mood when you return to the sanctuary, but you will have a second change to save the kitty.  You can increase the difficulty level to tricky f you want more tiles to clear.  There are also fewer obstacles , like locked tiles for example, although in general it should be fairly easy for the average player.  Worth mentioning are the basket obstacles.  These are shopping baskets that are full of items such as milk, flour etc.  You need to make the matches alongside the baskets to free the items inside, until finally they are empty and cleared from the board.  This give the match 3 aspect of the game a little different twist.

If you get stuck and haven’t made a match in  a while, you are helpfully given a hint to keep things moving.  As for the bonuses, you can earn a shape bonus if your tiles make matches in multiple directions and if you make larger combo matches you will earn more power ups.
Clearing the board isn’t your only objective of this game, however.  You are also required to gather resources in order to support  your kittens in the sanctuary.  There are three types of resources to gather during each round, which are gathered by matching the relevant tiles. If you can get the maximum of these resources beating the round, your kittens will get a mood bonus.  Though if you fail to meet this goal you will need to buy these resources from the shop.