If you want to make the game much easier for yourself, never let the AI get a Lab - they are very efficient at using them to infect and take over your base. The most useful lab skill is Infect - use it on all their barracks and it's game over for them. Sometimes it's better to stay behind neutral forts and build up your Lab and Barracks to win the game remotely. Also spam space + double click at the start to take over the maximum amount of blobs possible - the AI will generally move very slowly at the start and will be overcome.
Stage 7...it came down to me vs him, except I was a Fighter and he was a Testudon. Somehow the couple of shots I got off before the laser killed him :D
Game takes a metaphorical dump on the player on the last manor level - there's no way to avoid those barrels at the end, and jumping over them doesn't work either..."You're 99% of the way there? Gotta pay to complete it!" Seriously, DON'T spend a single kred on this waste of time.