I can't unlock Vanilla Crazy Cake

[damon]

I've beat the stages (Legitimately) multiple times and it still wo n't unlock >.<

[Yazite]

There has always been a problem with the achievement system in Portal. I still can't unlock Lab Rat, which is the very first achievement.

[Queens of the Shitpost]

dont know..but i have to get back to you when i have cleared my copy of portal of everything

[Cuddly Cat]

I can confirm this. I just tried to unlock Vanilla Crazy Cake three times and it won't unlock on Steam. In-Game though, it says I got the achievement already.

[DropsOfMars]

I... I cheated. Not sure if they fixed it, but last I checked you can noclip to the end, get out of noclip, remove cheats, save, leave, load save, then finish. It couldn't tell that I'd cheated.

It's how I finished all those impossible challenges. Not sure if it still works though. If you're going for legitimacy, I can't help you-- I sucked so bad at most of the challenges.