Consider earning the other achievements first to accrue more time cubes and weapon cubes to save time reaching Wave 4,000. Although you will get more time and weapon cubes progressively on higher waves, the time investment is not worth repeating them. Use the Dimensional Shift ability immediately after it becomes available again after its cooldown. Use the ability to reduce one hour from its cooldown as often as possible. Get to as high a wave as possible while using abilities. Eventually, your progress will begin to slow. At this point, continue grinding of Dimensional Shifts. Use all your abilities when you reach the Boss wave. If you cannot get past the Boss wave, accumulate more Dimensional Shifts. After some time you will be able to complete Wave 4,000. That wave has about 10 exp 240 health.