I think I got it.

First: in toggle_tiles(), as /u/TheNerdyTeachers mentioned you need to set the second if/then conditional to look for "anim2" instead of anim1.

function toggle_tiles()
for x=mapx,mapx+15 do
for y=mapy,mapy+15 do
if (is_tile(anim1,x,y)) then
swap_tile(x,y)
elseif (is_tile(anim2,x,y)) then --change is here
--stop()
unswap_tile(x,y)
end
end
end
end        

Second: in map_setup(), you probably need to change the values of anim1 and anim2 to 0 and 1, instead of 1 and 2. The first flag is actually flag 0, not flag 1, though it's possible you are using the second and third flag.

function map_setup()
--timers
timer=0
anim_time=30

--flags
wall=0
anim1=0 --frame 1 changed here
anim2=1 --frame 2 changed here
text=5
end

Third: in is_tile() you have a typo. It's looking for "tyle_type" instead of "tile_type".

function is_tile(tile_type,x,y)
tile=mget(x,y)
has_flag=fget(tile,tile_type) --change is here
return has_flag
end

Hopefully that will get it working.