When SS:EE came out a year ago, I questioned the respawn rate; it seemed a bit high. But with the Source Port release, it seems as if the developers cranked the respawn rate up to 11. Even on the Medical level - the introductory level and easiest of all the maps - the rate at which the mutants respawn is insane.

Case in point: I cleared the level to the looping corridor with the recharge unit. I had taken a few hits, so I decided to make a quick retreat back to the med-bay for some healing. On the way back I encounter 10 mutants (two groups of 3, one group of four), and then another three in the med-bay. I healed up, stepped back outside, and - on my way back - immediately faced off with six more mutants (a single, a group of two mutants, and a group of three). And this wasn't just a one time occurrence either; pretty much every time I walked down the main corridor I had to fight my way through a small horde, even if I had passed through just minutes before. By the time I finished the medical level the hallway was covered with dead mutants. And all this on "level 2" combat.

This heavy respawn doesn't occur everywhere but where it does, it is excessive. I am not sure if this is on purpose, or a bug specific to only certain machines or CPUs, but it absolutely destroys the immersion of the game.

On the plus side, at least the mutants all have their usual assortment of inventory junk; I finished the medical level with 57 medipatches in my inventory, and where I to grind a bit more (fairly easy to do with a Sparq, two recharge units and a nearby healing-bed) I could easily reach the 99-item cap. So all this respawning is making the game arguably easier, even if it isn't much fun.

I had the same issue. Gave me a fair surprise to say the least. My inventory was happy by the end of it however.

I uploaded a video of me just wandering up and down the main corridor of the medical level encountering all the respawns. It isn't very exciting to watch, but it will give you an idea of how excessive is the re-spawn rate. I killed twenty six mutants in just over nine minutes, which means the respawn rate is about one mutant every 20 seconds or so. See it here: https://youtu.be/RkjjzvJVzAo

It is possible this was done intentionally. While the original game was fairly slow paced, hanks to the modified engine, improved controls and far more powerful hardware, a player of the Enhanced Edition can now zoom through the levels at speeds rivaling the Doom-guy. Perhaps the developers changed the re-spawn rate to balance the difficulty.

But I don't really think this is the case; they didn't change anything else in the gameplay. It's more likely a bug. Maybe the timers controlling the re-spawn rate are running faster than expected - perhaps they were tied to CPU rate in the original? Or perhaps the game is creating multiple timers; the respawn rate seems to get worse the longer I keep playing.

Whatever the case, the re-spawn rate really needs to be toned down. It completely changes the mood of the game, and not for the better.