You shouls create a "trigger" line for groups of cannons. How would that work? cannons in a group would hold their fire until the line is crossed by the enemy, that way if you place the line closer you could kill more enemies in a row.
I got the archievement for killing two enemies with all the guns, then later i didn't save and the game failed, now no matter how many i kill with the seven guns i can't get the arch. What's going on?.
The green glow might be gone, but the poison is still working, try clicking the poisoned unit, hits won't take the poison of a unit, but it does wear off in time.
Another nice one: I'm battling 2 ghost almost at the final part of the game, one i cannot hit, the other i have been hitting over 15 MINUTES and haven't died yet, his hp: undefined. 2/5
I love the two slime bosses, you can't stop them with hit, and the have great magic attack, so they basically obliterate you (even having 6 Large Rejuvenation potions), well, this has happened at several stages of the game, that makes it so frustrating 3/5
Do the "go back in time", apparently it reduces the power of all the bosses, that's how i did it... That and the most powerful ship possible (the model doesn't matter, but it has to be a Elite tier one).