Pro tips: 1) upgrade your throttle etc till you have 2500 (mental maths people) then get money back and buy sprinkler. 2) use your mower to herd mobs together then spin for big bonuses. 3) if its not running on your lawn, don't chase it. you have a number to kill, and lawn damage = less money at end.
It wouldn't hurt to have a mini game to play while waiting on H/E/S regen. Maybe one with little h/e/s rewards to pass the time and help fill up bars a bit.
Pro tip: Grind game for 15-30 mins in survival mode and buy the mace or hammer and auto click (make sure to set it to on). Then go to lvl 1 of the Animal Lair and sit weapon midway between lair and mushrooms auto attacking. You can leave it sitting there for hrs on end racking up cash till you get sick of waiting and cash up on upgrades !
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