This guide will help you if you are still struggling with unlocking character or achievement Forest that requires 10 or more living when finish wave
What you get if do you it
If you can finish wave with 10 or more live trees you will get the achievement Forest
and unlock the character Cryptid
How to do it
My recommended character is the explorer with the stick.
Since the explorer has stat more tree spawn.
But he spawned with a lumberjack shirt that have ability to destroy trees in 1 hit which means you should avoid all items and weapons that granted projectiles.
For weapons, you can use any melee weapons because long-range weapons may unintentionally target trees.
Try to gather items that grant you luck or bonus tree items and try to go near trees as much as you can. If you keep doing it you might finish in 5 or 6 rounds.
For me, I can do it in the second round.
