Please correct me if I'm wrong, but if you say that PICO-8 "was not really enough", then I'm afraid you missed the whole point.
From the PICO-8 website:
"The harsh limitations of PICO-8 are carefully chosen to be fun to work with, encourage small but expressive designs and hopefully to give PICO-8 cartridges their own particular look and feel."
http://www.lexaloffle.com/pico-8.php
Not meaning to rain on your parade or anything ;)