Games Like Hex & Hunters

Hand-crafted Arsenal. Base weapons won't really carry you past a few rooms. Combine projectiles and modifiers inside many different weapons to craft the exact destruction machine you need. Build a wall-bouncing laser minigun, a precise line clearing sniper rifle or even a defensive teleporting tool.

Program your Dungeons. You don't have to go through the exact locations every run. Craft your own 3-tier sequences using crystals - choosing the biome, difficulty level, multipliers as well as special modifiers for each tier. Make your own plan for a run and receive ever increasing rewards for each finished tier.

Thinking 'bout your Builds. While you might do well enough with randomly assembled weapons to beat a Tier 1 boss, once you go deeper you will not survive unless you adapt your arsenal to various new defenses the enemies gain

Full 4-Player Co-op. Play solo or with up to 3 friends in online/LAN co-op, but beware that the difficulty will also increase with player count.