my personal record was lvl 106! upgraded the ground maximum whit 20% slow and rest acid. up just the cheapest turrets. did good. and your pistol is the best (not really but still it was better and cheaper then the shotgun and uzi)
I'm playing the game right now, I'm on level 95 and none of the monsters have even survived the second floor yet. I'll post later to say my final score.
You have to buy a gun first. Click on yourself and buy one of the guns, and then use the scroll wheel on your mouse to switch from the remote to the gun.
At the beginning, it's pretty easy. Just buy 3 machine gun turrets and a shotgun. Upgrade the turrets, but do not maximize the range. If you do, the guns will start trying to shoot through the floor and they'll be useless. I usually keep the range at 2. Once you have enough money, put a machine gun on every turret slot and upgrade it completely. For the floor, I had a repeating pattern of acid-slow-spikes, but it may be better to do acid-slow-spikes-slow. Fully upgrade shotgun and machine gun, you'll need them by about level 110-120.
I want to see if anyone can make it past 132 without it glitching like the screenshot above.