Need more work, but it's a good start. Bonuses should be accumulative, not replace the prior one. Different attack types should have additional effects, and mages should have an element that made them more vulnerable to one or another kind of magic.
Good game, but I think the selection of buildings is pretty biased. I got a lot of modern buildings in UK and then colosseum in rome! I think you should decide wheter to go for contemporary architecture or classical. Also find it rather hard to be precise with the cursor even if I know where a city is. Never got less than 60 km away. Maybe a zoom feature?
I've just played 8 times, but I think I can guess the rules CPU uses to play and I don't think the game is biased at all. Just take in account probabilities. If you roll a single die you have just a 2/6 chance of getting points, so it's better to bank the score unless you're on the trail for a lot of points.
overall a nice game but lacks something to really compete with other tower defense games. The range of shooting is too short and its cumbersome to rotate the pieces so the feature its rather useless