I'll be keeping the scrolling tilemapper, but the sprites will change radically over the course of development.
Controls: 2nd or up to jump, hold alpha to run, left/right arrow keys to move around.
EDIT: The entire source has been posted for those who want to take a gander at it.
The subroutines (movement, tilemapping) are all in ASLIMESR and the object routines (portal, keys) are in ASLMOBJR.
Note that this game is still pretty darn buggy. Especially the portals.