What are you taking about...? the rotate have no insidence on time... unless you talking about the rotate around the sun.
A planet's rotational speed / spin does have an effect on its gravity due to centrifugal force. A planet with a slightly higher mass, that also spins faster, could still exert an effective 1G on its surface because the centrifugal force pushes away from the center of gravity.
What you have to consider is that the MC still has to be able to survive on this planet. Its mass and spin would need to combine to be around 1G (or less). So you can have a planet with more mass and a higher rotation and still have an effective 1G. Though, at a certain point, the planet would have to rotate so quickly to make up for its higher mass that days would seem very short.
If you're proposing a planet that's larger and less dense per m³, that might work for survival, but its gravitational pull would still be 1G, and the relative passage of time would be unaffected.
You could have this planet rotate around a more massive star, but the result would still have to be a planet with a pull of around 1G (or less). Having a planet rotate too quickly around its star comes with its own set of problems as well.
The moon is a great example. Due to the way it moves relative to earth, clocks would be slower. But because of its lower gravity, clocks also run faster. In the end, a clock on the moon would run 54µs slower than on earth.
But for he story of the game too much will be not good...
On that we agree!
If relative time dilation is the goal, I'd instead suggest having the planet's star system a fraction of a light-year away from the event horizon of a black hole. Check out star S2 for some cool inspiration.