So what I have noticed, is that the enemy does not damage at all (duh!), including Shield lvl2-3 damage. Most of the time, instead of picking a large combo (and taking half damage), the opponent will pick the smallest combo that they can find instead, leaving you with the large combo, and the oppenent getting full damage :)
@Emoley: You can't really skip the car races, but you can initiate them, and then hit the 'x' in the corner to close the window. The race will still go on, and you can go and do something else. Hope it helps :)
Nice game, the only thing I don't like, is that sometimes when I had a letter fully in the magnifying glass, it counted it as a mis-click. Other than that good game :)