The section between core and frotz, if you don't go another way to get the item in the cystal section( sorry for not remember the name of it ), you are stuck there unless commit suicide.
Thanks for the reply! Your tip helped me to get through that part of the map and I was able to complete the demo, the rest I really enjoyed.
I think the reason I got stuck is that I didn't notice that much of a difference in speed between beginning my run in the room and starting in the previous room, because I took one look at that room and figured that I had to find a way to move faster, much like how a similar room taught me to run in Super Metroid. Thanks for your help!