1] On the first level, just hold the nail along the edge of the screen where the blobs and move the nail up and down along the edge, all of the blobs will basically die as soon as they spawn.
2] Use your money the level after you get it! Any upgrades will make the game much easier on you later, i.e. 1 shotting balloons, marshmellow people, and fireballs. You will make a lot of money in later levels so don't worry!
3] Use bombs! In a group of 3-4 people, you can use a bomb for 20 coins, and get the cost refunded and get the level done sooner than dragging 3 rolling things (sorry, the name escapes me) over the water and popping a blob.
4] Bombs from the Bomberbirds can destroy land creatures, and damage Behemoths.
5]Turrets can stack - meaning you can have more than 1 turret on one line of sight, so you can have two turrets shooting the same target.
6] After you finish with upgrades, you can easily destroy the enemies while you build up money for the 10 repairs after that.
Thanks for reading my guide, tips appreciated, Orclegion
Any upgrades will make the game much easier on you later, i.e. 1 shotting balloons, marshmellow people, and fireballs. You will make a lot of money in later levels so don't worry!
7] If the time is up for the end of the day, and it's not ending, then there is most likely a creature bugged at the beginning who will not move. You can usually bomb the edge of the screen to kill the creature and continue moving on.