The entire game is poorly written.
I get frame freezes and general lags the moment any special effects need to cast, except for gem effects and smoke. Fire and explosions (blinds) are especially bad, they slow down the game so much, that a single explosion can take up to five minutes.
That mission and the intro to it are buggy and glitching as hell, I've had to restart 15 times before I actually could try to defend against the bees and even then I couldn't protect the worms, cause I got non-stop frame freezes. In the end, I never completed it and just paid my way past it.
I got a good system, so the software must be written quite poorly:
Quad Core at ~2.7GHz
NVIDIA GeForce 9800 GTX (+) with 2GB RAM.
It's gotta be the dev's fault.