don't know why it glitches????

Looks like it only happens in the web player for whatever reason, but it doesn't afterwards and doesn't glitch offline. You could do a changepal() twice at the start of the program to make it less noticeable.
Also, you can replace pal(1,129,1) ... with
pal(split"129,130,131,132,133,134,135,136,137,138,139,140,141,142,143",1)
and pal(1, 1, 1) ... with just pal() to save tokens.

the glitch is normal - this is meant as a visual feedback you are entering a ‘secret’ mode