Normal mode with difficulty 10 isn't impossible, instead it is super hard. Normal wave can go up to difficulty 11. Mini wave on difficulty 31 is frame perfect, try it if you dare. mini+12 difficulty+3.4 speed for a decently challenging wave normal+-24 difficulty+7.2 speed for a medium and fast paced wave mini+-40 difficulty+10 speed for a challenging and fast spam
Warning:breaks at 15+ cps and runs a lot faster on higher fps. Scratch's fps is 30 fps.
