Fortify (itch)

This is a 2D Siege style game about defending your castle from goblins by building various tower defences. Between waves of enemies, the player has the opportunity to spend currency earned by defeating goblins on new weapons/defences and upgrading your character's skill tree to better prepare for the next, more difficult wave. Further to the onslaught of enemies, there are also random environmental effects which can both hinder the player and provide bonuses, with the odds skewed further against you the higher the difficulty that is selected at the start.