Double-Click the green flag. Tap the enemies to deal damage, collect coins, upgrade heroes and progress through as many zones as possible. This game has save codes, go to the settings tab in-game. (cog button). Use turbo mode to speed this up... From Level 200 (Inclusive), heroes get x4 multipliers every 25 lvls. From Level 1000 (Inclusive), heroes get x10 instead of x4 multipliers every 1000 levels.
This is the original version of Terraria Clicker before the remake. New version here: https://scratch.mit.edu/projects/332238824/ This is just here for people who want to continue trying the old version for whatever reason :)