Spirits DS is based upon an old Spectrum game and has been updated.

Release notes:

I just fixed a bug, sometimes, after loading a new map, sprite system crashes and game slowdown a lot (and sprites apear corrupted or just apear diferent sprites, some kind of memory overlap.) I added a function that clear all sprites from memory after i load new map, and seems it works fine now. Pls, i need some beta testers to fins this kind of bugs

http://palib.info/forum/modules/newbb/viewtopic.php?forum=9&post_id=20596#forumpost20596