I was impressed by an earlier mod along similar lines, Portal Stories: Mel. Hope this one is as well-done.
That one was great. Portal: Reloaded is also worth checking out. It adds a whole new portal type so its puzzles are quite different.
How are the new portals in Portal: Reloaded different?
Portals through time. Broke my brain playing the game, but a lot of fun.
In b4 “The 8-hour prequel is Portal”.
Portal is a really fast playthrough. Couple of hours beginning to end, tops.
Before I learnt it’s a prequel to Portal 2 (a presequel, if you will), I had a shiver from recalling what insane bullshit Portal: Prelude mod was. It was genuinely great in using, abusing portal mechanics, but even back then in my youth I couldn’t suffer through it. Shit has it’s own steep learning curve.
