I don't think the error is in your room function. I typed in your function and didn't get an error (although it would be a good idea to move the sprite definition code before the repeat loop. It seems unlikely you want to redefine it every frame).
My guess is you still have the while loop on about line 12 of your first screen shot causing problems. Can we see the code before the function call?
I think it was PacMan and Galaga Sprites and sound effects. But you weren't supposed to make pacman/galaga with it. Since it didn't work if you shared a program made using it with someone without the DLC it was worthless.
Put the introduction in a function.
REPEAT
INPUT "Skip opening? (YES or NO)"; SKIP$
UNTIL SKIP$ =="YES" OR SKIP$ =="NO"
IF SKIP$ =="NO" THEN
SHOW_INTRO
ENDIF
'Code for the rest of the game goes here.
...
END
DEF SHOW_INTRO
'Code for the intro goes here
END
Functions are always better than GOTO and GOSUB.
I've been watching Coding Train again. I modified the L System from making a tree to make a dragon curve instead. I also got the plant and sierpenski triangle examples from wikipedia working too.
Sorry, I will get back to my asteroids game soon.