Awesome fun, but one thing about difficulty

I think the game is great, but an issue is in the harder levels, where they can start off with even 8 or so enemies. No matter how good you are its not really possible to get rid of that many before a substantial amount of damage is done to you. After getting rid of them, if I do at all, I have too little health left to survive the rest of the level. Im not sure if its something Im doing wrong, but is there not another way to make the harder levels difficult without bombarding me with an impossible amount of als at start?

Jerf94 about Overkill