Beating easy

[Onlsaught1]

I've tried many methods out but I can't reach that 4000 kill mark to beat easy. The method I use is to have a bunch of tazers at where they spawn and then have the nukes blow them up. I don't know why but after around wave 340 I just end up losing and when I use a combonly I click on it when it's red and then it switches to fast for me to stop myself to a blue combonly which doesn't help me so should i just continue this combo or try to do my first ever laser chain? Also I can;t get the shockwave combo to work, I have made sure that the yellow shot first but it still doesnt work.

I know i spelled my name wrong but I think it is no use to make a different account.
How do u make a sig also?