The only connection to the lower areas seems to be through Exhaust Chute, but spikes make it impossible to reach the lower half of the Sensible Room and the Tomb of Mad Carew. A Wrinkle in Time is actually a dead end.
Is this all I can explore in the demo?
Best Answer
After spoiling myself and watching a few videos on Youtube I can say that yes, that's all that can be explored in the demo version.
What the demo fails to explain is that actually you start a "level" by reaching its starting sector in free roam through the game's world. That is, the full version does not yank you to a level selection screen after rescuing the first crew member. The opening in the pink area allows for further exploration.