Well, looking at the engine itself, it's a "tile-based" engine, but the number of objects on-screen that need to be checked at any one time isn't much. The player object has a set of 16 sensors (which are required for operations that overlap offset isn't appropriate for). It's not that many, but I'm still seeing the number of collision checks in the realm of nearly 2 million per second, which is kinda insane.
Besides, I did a re-examination of the debug results, and it provided an eye-opener. The events that take up the most CPU are the movement routines, which totals around 35% CPU use out of 45%, and considering it's a basic test level and it's still causing a lot of slowdown, that's not good at all. I think the way the engine itself is set up is incredibly inefficient, which is surprising, considering it's a port of a similar engine from Classic, which ran fine.