Jason’s Gem

Your mission here is to guide Jason through 15 screens in order to claim a
legendary gem for himself. First you must guide the spaceship down the screen
onto a teleport platform. Next you venture downwards through the caves,
shooting out gaps where neccessary. The latter 2/3 of your journey are
accomplished on foot. Only then can you change the course of history, and
erase the by-the-numbers poetry featured in the inlay.