This is a guide on a strategy I have for Ascension. I have gotten round 10+ with this solo strategy, and it works quite well.
Step 1: Round 1-2
Round 1: Buy the M14, knife only. If you have enough also buy quick revive. About 600 points should be left over at most
Round 2: If you have enough money, open the first 2 doors. Make a crawlie to make this easier on you, for it is easy to get overwhelmed
by zombies in the stairwells
Step 2: Rounds 3-4
Round 3: If getting overwhelmed, buy the MPL. If not, make a crawler with a grenade, open the last door, and hit the box until you run out of points or get a good weapon (Ray Gun, Machine Gun)
Round 4: 2 ways to go here. Either camp back in the centrifuge room longer. or open the door leading to PHD Flopper, call the lander, and hold out there. If you have Ray Gun, buy PHD Flopper. It can help quite a bit, by eliminating splash damage from the ray gun and all explosives.
Step 3: Monkey Round
At about round 5, the monkeys should come, but only if you have turned the power on. You can defend 1 perk, or attempt to run back and forth between the perks, which is hard because they are spaced apart alot, if you got a revive and PhD Flopper. Remember, the monkeys can stun when killed if close enough. Don't worry if you loose a perk, you can buy it again at the end of the round. The priority should be quick revive, because you can only buy it 3 times.
Step 4: Round 6-9
Rounds 6-7: Holding your position is the top priority. It is easy to get overwhelmed in PhD Flopper because of the large space. You should always have a lander there, and if you want, you can buy claymores.(Claymores are at the lunar lander in the junk yard, near Stamin-Up). You get 2 claymores per round, but you can stack them by placing them against a wall each round and then picking them all up when you need them the most.
Rounds 8-9: This is where it becomes harder. You should have a good 3000-5000 to spend, even if you kept buying ammo or frag grenades. Make a crawler in these rounds, and use the lunar landers. Activate the launch sequence and get back to PhD Flopper until you have enough points to Pack-A-Punch (PAP) a gun.
Check out this video (NOT BY ME) to see the rocket launch.http://www.youtube.com/watch?v=6twqOolwhTA
Step 5: Rounds 10+
At this point, it is homefree. You should have a Revive and enough points to PAP your guns. A tip for PAP a gun is to wait until it is out of ammo, because you can get all the ammo back and the PAP ammo. You should't camp in PAP because the 2 windows and the door can get overwhelming after a while. When you get back to PhD, you should remember to call the lander back, because it can be extremely helpful to have an escape at any time.
Circle Strategy: Run in a circle and let the zombies chase you. Then use a powerful weapon to take them out. Thanks to a guy in the comments for remembering this.