Thanks! Super cool that you liked it!
The thing with the skill tree was that I wanted the player to get excited and discover new skills as he plays (Even saw a GMTK episode on that!) but I just couldn't get it to click inside my head so at the end I decided to just put it all together in one giant skill tree. I think introducing each item or at least each branch to the player would be great! There is an example I just thought of in a game I took as inspiration. What they did there was instead of making the upgrades into one big skill tree, they just introduced the 2 options, so you had one simple choice: "What do you want: this or that?". That would certainly fit into my game and ease out the skill advancement process! While thinking about it now I should have at least put up some labels saying what would you achieve by going down a certain branch.