Another Animik :)
1) It's good that they didn't continue with the fourth installment because fans of the fourth game make up about 30% of the entire Heroes community.
2) In terms of gameplay mechanics, the third Heroes game has about as much in common with the fourth as the fourth does.
3) Regarding the graphics - I like it - but this is a subjective assessment.
Why do the Heroes need graphics? We want chess, and we get a silly cartoon.