Nice to hear :)
I think improving the base movement so that enemies turn around at the wall and find another way would be cool.
In terms of other interesting behaviours, I had some ideas while playing your game for enemies with different movement types.
- Enemies that also can use a dash ability to phase through walls
- Enemies that can go through walls but are slowed down while doing so
- Enemies that can teleport by creating a short-lived portal on the ground or perhaps on normal walls
- Enemies that try to escape if the distance to the player is too close because they can't attack without a weapon or use a range weapon
- Enemies that can use a sprint ability when they are too far away from the player
Hope I could give some inspiration or useful ideas :)