[SP] Portal Stories Mel: Past Power
I've had the same issues on my mac.. downloaded The Core sometime ago, and that was unplayable as well.. Played great on one of the Pcs' at my shop tho...
As said before, it's a known issue for macs... Moth is looking into it!
Hopefully a fix for macs will be out soon 
The point about trouble on Mac OS has already been made, but to be thorough, here is what we see when we click on the Stories Demo in the Steam window:
Just finished it and i loved it!
The fps was noticeable at some areas but i didn't bother much since i was prepared by the posts in here. Not that the... fps explosion when i triggered the blue gel didn't scare me. 
Anyway, great work so far, can't wait to see the full mod. Now i'll track this on moddb with even more passion.
Fabulous start to your longer mod....the old style is a personal favorite...
Obvious that I needed blue gel to finish, but where had me stumped for quite a while - kind of hard to find.
Thanks for creating.....look forward to more...
would you be able to tell how to create one, or where to find tutorials about them?
With much lag, I could run the map without crashing, though I have some old intel card from 2007.
More information Here
"Pretty is better than ugly, but if it doesn't work, ugly is better than pretty"
-Phyton
The demo was superb - what a wonderful and intriguing environment.
I did not want it to end. The puzzles were easy which is one thing I have noticed on these mega-mods. You should try to add difficulty if possible.
The lag is a problem. I have a fast ASrock P67 Mobo with an i7-2600 Sandy-bridge CPU, and an m4 SSD. But it still had significant lag that started when I left the first room and entered the orange gel room. For me it was still perfectly playable . . but on an average PC it might really be too slow.
I think you might want to remove the fire. That often causes significant lag and I suspect that is the main culprit.
My fps started out fine then dipped way down to 15 fps as I left the first room on the lowered catwalk. It did get a bit better later (about 22 fps) but still was kinda jerky.
Still - great job, a lot of fun, and the place is a fantasy world that feels like a storybook.
Reporting your lag experiences is only helpful to us if you attach details of your video hardware.
Integrated graphics (ie: onboard) are obviously not up to the job of rendering this map, which is why the mod has its own seperate graphics settings 
"Such monstrous sucking-constructions aren't built within one afternoon"
Can't share the complaints about lag or fps loss. I'm having solid 60 fps while recording (fixed rate, due to recording settings) and 100+ while not recording (sometimes dropping down to 90-ish, but that's not laggy at all). Always going with max graphical settings.
Here is my recorded run:
jKkmUjzmSbs
(Link: http://www.youtube.com/watch?v=jKkmUjzmSbs)
However, it's not really a blindrun this time because I'm one of lpfreaky90's playtesters.
Portal 2 Playlists: videos 1-200 | videos 201-400 | videos 401-600 | videos 601-800 | videos 801-1000 | videos 1001-1200