I realize that the developers want to get the big important stuff done as soon as possible before concentrating on "quality of life" improvements. But I did have one small suggestion. Whenever you level up, could there be some type of sound that plays? Like a "DING!" or a computer saying "Mining Level Increased". I had been playing for a few hours and wondering why I hadn't leveled up, until I looked at my character stats and realized I had gained 3 levels.

a message on your hud does appear when you level up. you probably missed it amidst the chat text.