The INC command itself is not going to cause the error… and I don't have enough context but if you are using WAIT in your loop, change it to VSYNC 1. SPCHR I don't think writes to the stack (which I just tested).
GSPOIT’s parameters should probably be float as it can only read pixel within a whole number. I’m not really sure what you are trying to do, are you trying to create a sprite or a drawing of a sprite on the graphics screen?
Not with this language... it’s not powerful enough. And with the raycaster, you should replace LOAD with USE and then remove the USE 1. It will be faster and more efficient.
Do you mean the sprite page? you can use GPAGE 0,4 and use GSPOIT(X,Y) to get the color value of the sprite. You can also use GPAGE 4,4 to display and edit the sprite sheet.
Your sprites are 16 pixels by 16 pixels so if you want the sprites right next to each other, then use spofs with increments of 16. Also doesn’t use the same management number for more then one sprite. For example:
SPSET 0,1
SPSET 1,1
I believe only one of your sprites is appearing so changing the management numbers should fix this. Ask if you need anything.