Thanks doommetal! You can probably imagine the amount of tuning I did as the Unity physics engine is a constant puzzle. I had to stop myself after tinkering with arrow physics, gold physics and the rest for much too long :) I had the gold much more 'explodey' at one point, which was a lot of fun, but the gold liked to blow through the walls which is pretty upsetting for the player.
I'll get the player movement locked in my next release, because I agree - a bit more damping and a bit more speed would definitely improve the movement feel.