Weapons feel like they are made out of paper rather than powerful spells and most levels are just a series of predictably linked square rooms. Every upgrade is something boring like "carry 10% more ammo for a specific weapon" and the playable characters are equally as uninteresting.
Ziggurat is a nice concept for a game that has been done better by other developers. It's not terrible, but you can't just slap roguelite mechanics on top of a mediocre shooter and expect it to be good.