All Kao 2 runs need to be capped to 60FPS. This cap was implemented after a vote by Kao 2 runners, as not everyone is able to play at 60+fps, and playing at a high framerate gives you an unfair advantage.
It looks like at 55 fps and above, the physics slowly start breaking. The higher the framerate, the more likely the physics will break. Bullets will travel farther in Lair of Poison, certain objects like the balloons in Great Trees will catapult you away at high framerate: Loading screens are also faster at high fps. These are the advantages high framerate can have, below are some other effects of a high framerate.
Cutscenes seems to play fastest at low fps. The higher the fps the longer cutscenes take to finish, resulting in awkward pauses between sentences. The animation for the butterflies also plays too fast.
I did notice that some animation did not fully finish at 50 fps, like the ''Where are you going, have you got the money'' animation. On 50 fps he does not tap his palm with his hand, while at 60 he taps it twice. At 120 he taps his palm 4 times.
Also, at 1000+ fps, some animations, such as parrot walking in his cage, play a lot faster than normal.
So, all in all The game doesn't seem to have a completely perfect FPS, but 60 fps seems to be a good balance
You can do so by either enabling V-sync in your graphics card settings or using programs such as RivaTuner or Dxtory.