Do you know if it is possible to use solarus on a raspberry pi.
I am not sure about the Solarus editor, but I believe the engine works. It has not been tested much on Raspberry Pi. I believe only one person has tested it.
This is a link to the only test I know of. You will probably have to compile it.
http://forum.solarus-games.org/index.php/topic,648.msg3290.html#msg3290
Yes it works with RetroPie.