Thanks for playing!
The lack of tutorial is definitely the biggest sticking point, along with the controls and lack of UI tooltips.
The main loop I was trying to target was "Find cool stuff > put it together > have an op build" so I'm glad to hear you had fun with all the stuff you found!
Originally the enemies were going to be a major source of the items to make them more important to fight and yea, it ultimately is just a portal rush. There was also going to be an enemy on the floor that was a "floor boss" and dropped an exit key (like the game Dark Cloud if you know it) but I got overwhelmed with all the art that would be required to flesh such a system out.
I wanted the areas to have some more variety but wanted to make sure the rest worked first. In hindsight, limiting it to three areas with a little more depth would have been much better I think.