What would life be like on a planet with high gravity?

The best example, the Elcor from Mass Effect:

On a planet with a high force of gravity, any fall can be fatal, therefore, each life form should be robust and quadrupedal to achieve safe passage and a low center of gravity.

Planets with high gravity tend to have denser and more viscous atmospheres, so lungs would need to be much stronger to suck in "air" and hearts would need to be much stronger to pump blood against the gravitational pull. Veins probably also have muscles, just like our arteries. The oxygen should be much more concentrated, so the animals should be able to get bigger.

Flying animals are unlikely to appear on such planets unless the atmosphere is dense enough to support their weight, like whales in water.

Whales on planets with high gravitational pull would tend to be very small, but also extremely robust. I'm not sure how the volcanoes would behave, as they would only erupt after reaching unimaginable pressures, which would mean that eruptions would be rare, but spectacular!