In my various ramblings about our cat, Cleo, I think I mentioned that she wasn't at all interested in toys, and didn't really play. That certainly used to be true: if you rolled a ball towards her, dangled string, or jiggled a toy mouse, she would look at it steadily, then look at you, then walk away. But in the past couple of months she's started getting playful. I think part of the change is down to her being stronger and more energetic now that she's put a bit of weight back on. When we first got her, she didn't have the strength to jump up onto the window sills on her own, and we'd find her clinging on to the top of the radiator below the window with her front paws, vainly scrabbling to get on the sill. Now she can jump straight on to the sill unassisted, though she still feigns helplessness when she gets "trapped" behind the curtains, and there's a good deal of chirruping and Eric Morecambe-style curtain waggling until we open them for her.
She's always keen to play first thing in the morning (when we're trying to get our breakfast) and in the early evening (when we're trying to cook dinner). She loves a ping-pong ball toy which is covered in fake leopard fur, and has some beads rattling inside. She waits on the stairs, having previously engaged Pounce Mode; body pressed into the stair tread, ears horizontal, and a wild gleam in her eyes. We rattle the ball to grab her attention, then throw it over her head. She flings herself after it, often catching it rather gracefully in mid-air, or hurtling after it up or down the stairs. She does the 'holding-the-ball-with-front-paws-while-biffing-it-with-back-feet' thing, and sometimes gets distracted, then pounces back on the ball when its guard is lowered (like Cato and Clouseau). Eventually, the ball drops back down the stairs, and we throw it again, repeating until we get bored or our porridge goes cold. She seems to enjoy it, and it's pretty entertaining for us, too.