[Lomgren]

I'm pretty sure that is done with a 'noob code' you know like;

if (keydown(0)){
playery--;
}
and so on,

but then again, I suppose there is nothing stopping this from producing the same effect;

for (i=0; i<4; i++) {
if (keydown(i)) {
playerx+=vecx(i);
playery+=vecy(i);
}
}