Cheese method
Requires remote console. See here for how to use it. --remote-debugging-port=9222
Start a new game for an achievement, then enter the following in the console:
var r = cr_getC2Runtime();
Enter each of the following commands one at a time:
r.changelayout = r.layouts['level5'];
r.changelayout = r.layouts['level10'];
r.changelayout = r.layouts['level15'];
r.changelayout = r.layouts['level19'];
r.changelayout = r.layouts['ending'];
For the next set, after each one, you will need to load a level, for example with this command:
r.changelayout = r.layouts['level1'];
So use that command after each one of these, again using one at a time:
r.all_global_vars[13].data = 'rifle';
r.all_global_vars[13].data = 'auto';
r.all_global_vars[13].data = 'mgun';
r.all_global_vars[13].data = 'laser';
r.all_global_vars[13].data = 'lasertag';
