Some levels are a lot easier with orcs. Just use a lot of totems, and when they summon 60 units when they are halfway dead, you can kill all the normal ones so you just have to kill the dragons, angels, devils, and bosses.
to get hobbits: read instructions and view credits, dwarf:play yhe game 3 times, bombermans: loose 3 times,angel:get all races maxed out in upgrades,red dragon:kill "the end" boss, devil: kill the very last boss
4/5 I liked the first better, but still good