Immortal Redneck

The merchant is closed when you first start the game. To open him, you first need to buyenough boxes in the skill tree to level up. The node costs 1500 gold.

You will need to get good runs in to earn enough gold to buy the nodes first, so don’t worry too much about this to start with. The further you advance through the pyramid, the more you earn. To give perspective, I earned about 4-500 gold on my first run. After 5 attempts, I earned over 2200 gold. So focus on your attack, defense upgrades to last longer in each run and you’ll soon have enough to unlock the merchant.

Here is how to unlock the merchant and even unlock some other achievements while you're at it!