This achievement is simple but time consuming.
You can amass the points over time. Even if you die and as long as you continue (aka reinforcements in this game), you will unlock this.
However, do not quit. If you do you'll start all over again from the beginning.
If you are hardcore enough and do not die or use nukes EVER, then go for the Cannon Happy achievement as well (good luck, this will require serious skills.. lol)
MegaManSurvives solution for Cannon Happy achievement gives excellent tips and suggestions on how to properly equip your tank so you can withstand the assault.
Thanks MegaManSurvives for the tips!