I downloaded Sanctum on Steam tonight. I was able to get through the first 19 levels of the Mine without the shield taking any damage, but I've now tried 4 times on level 20 and I can never take down the Big Walker. Is it possible or is he just there to absorb damage?
I have several laser towers upgraded to level 5 and I freeze him twice in their area (he has to pass them twice). I'm also critting him with the sniper rifle constantly, but I never even get close to taking him out.
Any tricks or tactics would be much appreciated, but I'd also just like to know if it's possible at all.