Speaking of highbrow philosophy - it had never appealed to me in Lem's works. What I praise him for is "The Invincible", which is sci-fi drama, and the series about Ijon Tichy, which is sci-fi comedy/satire. Even if there was philosophy in there, it was delivered directly, through emotions.
I remember the moment in my life when I was genuinely scared that I might actually die from laughter. I was suffocating and helpless, my abs seemed to be about to break. It happened when I was reading one of the Ijon Tichy stories.