I have a few suggestions.
- Have separate volume slider for voices.
-Special event happens when you injure the announcer or king.
-seperate sword swing style from character moving keys
-Spider tron 6000 could have two heads, both shoot, with six legs. There could be variants with this. Both shoot bombs, one could and one arrow that is faster, or both shoot arrows.
- endless waves mode
I really like what you have so far. Keep up the good work!