Would a Giant Move Slower?

The larger a creature is, the slower it moves because it has more mass, and the more mass you have, the longer it takes to accelerate that mass up to speed.

Would a giant actually move slower?

Overall, the giant is faster than you are. However, with respect to his own body, he appears to move in slow motion. Here's a thought experiment: if you're 6ft tall, you can probably run at more or less 6ft/second.

Do bigger things move faster?

Heavier things have a greater gravitational force AND heavier things have a lower acceleration. It turns out that these two effects exactly cancel to make falling objects have the same acceleration regardless of mass.