Also, you get to meet the Weighted Companion Cube!
The Companion Cube exists in one level only and it has hearts on it because testers kept leaving the box behind when it was needed for the level's puzzles. It's
just a box, identical to every other box in the game except for the hearts.
Anyway: I thought this game was pretty neat. However, being 2D greatly limits the range of puzzle possibilities, and the game gives you the gun right away. (The real Portal very carefully withholds the gun until it's clear the player understands all the basic mechanics of portals.) It was an interesting diversion, but on the whole I found it dissatisfying.
However I thought it was
very noble that the game didn't mention cake at all (at least for as far in as I got- which was a good ways in, though I didn't beat the game). Or at least, I saw no such mentions. Maybe there were inter-level cutscenes that I skipped without knowing they were there. Whatever.