The creator said the engine is basicly writen for simplicity and brute force.
Meaning, he has writen it to get the job done and thats it. So, no optomisations or fancy algorithms have been implimented.
It does what it does, but it doesnt try to be super cool/fast/effiecent! - I dont think its a product to ment to compete with ID's software, but more of a hobby project.
It also sounds like its a bit of a learning platform. In that case, does he make the source avaliable?