Mount Everest approaches the tallest possible mountain. In a 1.5g gravity well mountains would be much lower.
A thicker atmosphere coupled with higher gravity might lead to increased erosion. A key parameter is the rotational speed of the planet. All other beings being equal I would expect it to be greater than Earth due to the increase in mass, so the ground speed at the equator compared to the poles would be greater leading to faster winds.
Rivers would run faster causing more rapid erosion as silt and debris where dragged along at a faster rate.
Tectonic activity would require more energy input to fight the increase in gravity so tension might build more slowly but be released with greater violence.
The basic topography of the oceans would probably remain as they are on Earth, except the continental shelves might slope more gradually.
Humans would find such an environment impossible to survive in the long term. The strain on the body over even a short period such as a week would be extreme. Native animals would adapt with stronger shorter more muscular bodies.
Side note: assuming landing on a 1.5g world was possible (maybe) it might well be impossible to leave again. 1g is a massive gravitational well that is very difficult to escape from. The rocket equation has exponential terms and increasing to 1.5g would make escape impossible with conventional chemical rockets.