Before verifying that in-game experience and money numbers are fine, I decided to revisit main gameplay and ended up making few changes to it.
Both UI and gameplay mechanics were improved (I think).
Current UI (yet to complete):
As a part of UI redesign, icon for all available actions were added. Another subject for later improvement.
Experience gain by level was calculated. The first attempt revealed some discrepancy with lower levels requiring more experience than higher ones; however after two more attempts the numbers become much better (one of rooms was assigned a higher level),
Icons for wardrobe items
Icons were created to all (for now) items Ryo can wear. These icons too are a subject for later improvements; the point now is to see them all in-game and learn if UI needs any adjustments.