Balancing is the aspect of the game that was left for the very end of our time limit, so in result the game is not that balanced.
Yes, fleeing is intended. It gives no new cards, while actually defeating an enemy is often a big source of new ones and is supposed to take more effort and risk.
It's also very easy to farm early enemies for cards, overfill the hand and never run out of resources after. We thought about a couple ways to fix this.
Either there could be a time penalty that prevents this, so the longer you take for your descent, the harder the game gets. Otherwise, we could always just find a way to implement a hand limit.