yeah, more or less. still one of the funner games ive played in recent years tho. definitely worth the buy because i've played through it a number of times. it was actually the game i was looking forward to most when Orange Box came out.
the dialogue is witty, puzzles get more and more challenging as you go on (its got a good difficulty curve), hence "Thinking with Portals" because its really the only game that lets you break the mold of conventional thinking due to its unique gameplay mechanic