I honestly just want to say thanks so much for taking the time out of your day to leave this level of investment into trying to make this game truly great.
To start off, I do agree with you on the items point, they feel kind of bland at the moment, maybe this was due to me trying to push the game out asap, or not sure of what ideas to have for items.
I would like this game to have the Binding of Isaac Synergistic feel, that's the future goal I would like to have with this game for sure, and I definitely want to revamp the items to make them not only fun, but more engaging.
Duplicate items was definitely an over site on my side, that is already going to be in the works of getting fixed.
Endless mode... after having some friends play it, definitely scales to a point where its truly not even that fun for the player, and I plan on re-adjusting the difficulty to make it feel more rewarding.
Speaking of rewarding I like the idea of giving the player awards for eliminating enemies, not so much just getting an item afterwards but giving them possibly extra items if they finish within a timely matter.
Also thanks for taking a note to just trying the game and not only that but practically studying the game, I really appreciate it, and hope to see you through the development of this project! It really does mean a lot to me!