Bouncing path of all bolts drawn.
With the cursor being always visible I was able to observe that the application calculates and 'draws' the bouncing path of every bolt. Even those that do not bounce. Acid, Fire, Frost.
This takes up time. With the graphics introduced more processing is needed. This makes everything slower. It must be painfully slow on an older machine.
I'm no programmer, but it would be a great improvement speed wise if these non-bouncing bolts 'stopped' when they hit a wall.
Black Dragon Vault was very annoying.