Top down movement in pico8

gistfile1.p8

-- if you find this interesting
-- checkout the full source code at https://github.com/eguneys/pico8-jam/blob/master/alta.p8

local intheta = atan2(-ix, -iy)
 local diftheta = player.theta - intheta

 if ix ~= 0 or iy ~= 0 then
  player.theta = appr(player.theta, intheta, 0.08)

  if abs(diftheta) < 0.25 then
   player.daccel = appr(player.daccel, 3, 0.3)
  else
   player.daccel = appr(player.daccel, 0, 1)
  end
 else
  player.daccel = appr(player.daccel, 0, 0.3)
 end