Ironically the design is actually opposite with fewer and fewer free pipes per level. Ie it starts out being like pipe dream, and ends being like factorio.
As for the difficulty curve that was a submission mistake . I put the first version up 10 minutes before the deadline and didn't realize wouldn't be able to submit more tweaks to get the challenge right. I'm glad I left something that is playable though the other alternative might have been to have a difficulty challenge so high you can never get past the 1st level.