I’ve been playing Portal in 15 minute chunks every few days, so I s’pose I should’ve finished after 1.2 sessions, but I just completed it last night, and am therefore now singing that song, which really is superb.
I did have to resort to spoilers once near the end (I was convinced four hydraulic platforms, with one at a slightly different height, were vital to progression somehow when they turned out to be entirely superfluous), but other than that the puzzles continued to be nicely balanced.
The only mystery I’m left with is… what’s the the companion cube-mania? Having seen the carved pumpkins, full size costumes, plush toys, freezers etc., I thought at some point there’d be an amazing, cube-defining moment in the game but… erm… no. It’s just a box. Isn’t it?