Madness: Project Nexus
I didn't realize this before, but your HP goes up as you level up. Since my last posting on Project Nexus, I had roughly 100 HP. Now I'm lvl 200 with 216 HP. Stats that increase your survivability are Tactics and Endurance, and the first perk of Dexterity. If you're a big picture kind of guy going for the Genocider medal, you may opt out on survivability stats.
Suicide has obviously taken longer for me. It seems that your Tac-Bar refreshes everytime you take a hit to your HP, so a low Tac-Bar may be desirable. Alternatively, you could suicide at a higher wave. For instance, if you suicide on wave 29-30, the first round of enemies will have 1 agent, 1 unitech agent, and the rest special agents. If you opt to suicide on wave 31, the first round of enemies will have 3 unitech agents, and the rest special agents. Unitech agents are much better at killing you than the other guys, so this seems like a viable strategy to suicide on later waves than usual to keep your overall kills-per-minute as high as possible.
It's still worth stressing that G03LMs will start appearing very frequently beyond wave 35, and the PITA red ones appear on wave 37 and beyond, so don't try to go in too deep.