game_w=128
game_h=128

function _init()
 plat={}
 plat.w=game_w
 plat.h=game_h
 plat.x=0
 plat.y=game_h/2
 
 player={}
 player.w=8
 player.h=8
 player.x=game_w/2
 player.y=plat.y-player.h
 player.spr=1
 player.spd=2
 player.vy=0
 player.start_vy=-5
 player.in_air=false
 
 grav=.5
end

function _update()
 if btn(➡️) then
  if player.x+player.w<game_w then
   player.x+=player.spd
  end
 end
 if btn(⬅️) then
  if player.x>0 then
   player.x-=player.spd
  end
 end
 if btnp(❎) then
  if player.vy==0 then
   player.vy=player.start_vy
   player.in_air=true
  end
 end
 if player.in_air then
  player.y+=player.vy
  player.vy+=grav
 end
 if player.y+player.h>=plat.y then
  player.vy=0
  player.in_air=false
 end
end

function _draw()
 cls()
 rectfill(plat.x,plat.y,plat.x+plat.w-1,plat.y+plat.h-1,7)
 spr(player.spr,player.x,player.y)
end