Game mechanic/feature ideas

Hi there, I am currently working on a game where the basic setting is that it takes place in a maze which is randomly generated every time you start the game or respawn. The player has to solve the maze and get through a bunch of enemies and in the end find and face a boss to finish a particular level. I have worked on a couple of enemies and items, for example, there is a simple projectile shooting enemy, one that shoots poison droplets, one that just simply chases the player etc. I have also included some items like a couple of different weapons and items like one that freezes all enemies that are within the view of the camera, another item allows the player to go through the maze walls for a short period of time etc.

I have been so caught up on the technical part of the game that it has kind of made me turn a blind eye to making the game well......"fun". I have implemented almost all the features I wanted to but then again it kind of feels like there is something missing. I was wondering if you could help me with some ideas like adding some more items or making the maze itself a lot more challenging and exciting. In my opinion the maze itself seems a little empty and does have some room for improvement but I am having a hard time figuring that out.

Any help is appreciated. Thanks :)

Read Derek Yu's Spelunky book. You can find other resources about roguelikes and roguelites online, but Yu provides a lot of great personal insights into finding the fun in these kinds of games that are hard to come across in a lot of online resources. Most of the book is precisely about taking a game like you describe and making it really fun.