Lightning and Goo - Grasslands on Easy - Perfect Score

Having trouble beating grasslands on easy without losing any lives? Here's a great strategy on how to do it.

General Strategy Put as many lightning towers in the red area as possible.  This will kill air units effectively.  Force ground units to double back past all towers using rows.  Use diagonal rows because they force ground units to move slower by making more turns.
Round 0 Start with 3 diagonal gatling towers
Round 5 Upgrade the 3 towers
Round 12 You should have enough for your first lightning tower.  Also add a goo tower to start slowing things down.
Round 15 Save up for another lightning tower.
Round 18 Start building the first turn.  Add a few more gatling towers and another goo tower.
Round 22 Upgrade one of your first lightning towers and add another one along with a goo tower to the 2nd row.  Have to get the 2nd row ready for the flying enemies.
Round 25 Fully upgrade goo towers and add another lightning tower to row 2.
Round 27 Finish off row 2 with a goo tower and 2 gatling towers.
Round 31 Fully upgrade a lightning tower in row 1.  Also add a full goo tower above it.
Round 36 Upgrade the other lightning tower in row 1 to full.  Add another lightning tower beneath it as well.
Round 48 Fully upgrade all row 1 lightning towers.  Add a new one to the second row behind the goo gun.  Upgrade each row 2 lightning tower to lvl 2.  Anything that makes the 1st turn should get decimated 2nd time through.
Round 51 Start the 3rd row with 3 gatlings.
Round 55 Add another lightning tower to the 2nd row and start fully upgrading them.  Also throw a goo tower in row 3 and the bottom of the 1st row.
Round 67 Alternate lightning/goo in row 3.  Add another lightning tower to the bottom of the 2nd row.
Round 80 It's pretty repetitive here on out.  Add a few more lightning tower to row 3, start upgrading them, then start the 4th row.
Round 92 The only thing to protect against is late level flying rounds.  Upgrade row 3 and add a few more lightning towers to row 4.
Round 99 Smooth sailing...
Round 100 No problems at all.  No towers sold, no baddies made it through = perfect score.

This strategy is great for normal difficulty as well. Next post will show how to use a form of this to beat normal mode.