Well, his perception and grasp of the Force is amazing, as his shatterpoint technique as a youngling surpassed that of most Jedi Masters. Some examples:
- After being set up and captured, he's questioned by a man named Geptun: instantly, revealed in his mind are a dozen points on the man's body where a single blow would break him.
- A Corusca gem is described as being hard enough to withstand a full-on blow from a 5 kg hammer. Mace could shatter it with a gentle tap on its weak points, which are nigh impossible to find.
- When trying to rescue a group of children in an oven of a steamcrawler, he uses the Force to swiftly trace the network of cracks and fissures to a single weak point, and then brings an entire cliff down.
- He literally rides this like a wave, manipulating parts of its course to get to the sandcrawler.
His raw power is impressive as well:
- After he triggers a landslide, one of the kids in the vehicle shoot at him, disrupting his focus. The landslide is lost from his control, and begins to drag the steamcrawler into a volcano. On his back, Mace manages to grip and suspend - in the air - the entire landslide, which was said to consist of several hundred metric tons of rock, earth, and the ilk.
- In When They Were Brothers, he gets pissed off at Grievous, who'd just killed Adi Gallia, and slams him into the ground with a massive swoop.
And on a side note, when he was but fourteen and went to Hurikane to find the elements of his almost prophesized lightsaber, he was frightened by a band of natives, and hurled them into an abyss.
I'd have to say, however, that Mace's most impressive feats are in the ways he manipulates his physical self with the Force. There are far too many to list, but here're a couple.
- Against Kar Vastor, he launches himself with such speed and power that he and the shaman are suspended in the air for enough time to engage in a short, airborne brawl.
- In the same battle, he fires off six combination blows - two elbows, a pair of crosses, a knee to the midsection, and a palm to the face - before his enemy can blink.
If you want martial and dueling feats as well, I can provide some.