How do i make my games Framerate More consistent

I happen to notice to speed of the game slow down at times doing the Run of the Game where you play as the Character. which include.

Running into a Certain Enemy. at a Specific area.

the framerate drops, what can i do to keep it have a reasonable speed and be more Consistent?

Common sources of frame rate slowdown include exceeding fill rate capabilities, physics and collision calculations, inefficient gameplay event loops, and pathfinding, among others.

You'll need to first identify what is causing your problem to fix it.

So i got a Stage,and Enemies, Enemy A, (BlueSwordGuy) Enemy B (BlueBowGuy) And Enemy C (BlueMageGuy) in which there are two Areas where you have to slay enemies in order to progress, you cannot continue untill its done. the first one goes fine without any noticable slowdowns in framerate, but the second one it slows down a more whenever a "Enemy A" is on screen, that does not happen when it is a Enemy B or C?

I still havent Figured it out, but i might suspect it has something to do with there being too many of the same Enemy overall in the same layout...