save the stats of the enemies into a file
var killed_e[50]
[...]
//enemy killed
killed_e[id_of_enemy] = 1;
[...]
var fhandle = file_open_write("levelname_here.something");
var i;
for(i=0; i<50; i++)
{
file_var_write(fhandle, killed_e[i]);
}
file_close(fhandle);
now.. after level_load, you read out the file:
var fhandle = file_open_read("levelname_again.something");
var i;
for(i=0; i<50; i++)
{
killed_e[i] = file_var_read(fhandle);
if(killed_e[i] == 1)
{
//call enemy death code
}
}
file_close(fhandle);
^^