Try this out..
`setup
sync on
sync rate 0
cls rgb(0,0,255)
`coordinates
x#=0
y#=240
`variables
v#=0
c#=0
c2#=rnd(5)
`colors
r=0
g=128
b=0
mg#=255
`background color
bkb=0
bky=0
`main loop
do
`sky
inc bkb
inc bky
if bkb>255 then bkb=255
ink rgb(0,0,bkb),backgd
line 0,bky,639,bky
`draw landscape
if bky>300
dec mg#,0.2
if mg#<0 then mg#=0
inc c2#,rnd(10)
inc c#,tan(c2#)
v#=wrapvalue(v#+sin(c#))
ink rgb(0,255,0),0
box 0,300,639,479
inc x#
y#=sin(v#)*50+200
ink rgb(r,int(mg#),b),0
box x#-1,y#-1,x#+1,y#+150
ink rgb(250,250,250),0
sn#=wrapvalue(sn#-2.0)
snow#=cos(sn#)*5
box x#-1,y#-1,x#+1,230+snow#
endif
`end loop
sync
loop
Your signature has been erased by a mod because it's larger than 600x120...