I find it effective to play off of the bot's range with their weapons. With the longer range weapons, you can keep running from the enemy while shooting at them when they can't (if they have a shorter range weapon). Same can go for the opposite. The longer range weapons generally can't shoot your if you're RIGHT on top of them. Use a short range weapon to get close and slaughter them as they try to escape.
Just a few examples though. Hope it helps! =D
I can see why people like this game, it just doesn't strike my fancy. =( I wish I actually liked it, then I'd join the cool people that like this game. lol
I find the Dryad Magus a very useful combo with high Willpower and Intelect. if you're swarmed by enemies, run to the nearest narrow hallway and cast Vine Field to cover your escape accompanied with Inferno in the same spot. They'll take damage as their slowed by Vine Field. Then pelt them with Ignite or cast Entangle to kepp them within the effects of Inferno. Hope this helps!