I helped design the power progression and game systems, as well as their usage for the meta-story of the game (think Hades). The game utilizes essentially the DnD ruleset for playing and statistics, but for the purposes of a roguelike game we adjusted alot of them.

I was solely responsible for level design and encounter design. The game uses a grid for combat calculations, so every level had to be perfectly aligned to allow for proper combat. Due to the procedural encounters, specific level layouts had to offer a variety of different combat options, which made designing them quite challenging. Every level had to offer opportunities to play different depending on enemy types, starting position and party level. So a variety of carefully placed choke points, open areas, elevations and corridors was necesarry.
I also worked with a limited amount of bought assets for this project, so I was quite limited in creating different "moods" for the different level layouts. I looked to possible past uses of the spaces for inspiration, so some levels seem like an old library, or a cellar and so on. I also tweaked lighting and ambiance to create a different "feel" without changing any assets.

For encounter design I made use of all the different ways levels could be approached by designing the encounters in a way were the natural level layout would benefit the player, or hinder them. Enemy archers on high ground would have a big advantage, but letting the players spawn at this position allows for more challenging enemies to try to swarm them.
For more variety I set up "stealth-levels" where players could outsmart enemy patrol paths and start combat on their terms.