It was around level 16 that it stopped updating level. Reached level 20 and was over. Unsure if internally it was raising level and delivering bonuses, the indicator remained at 48/10000 or around. Is there anything beyond level 20? Looks impossible to beat but the summary does mention bosses, plural.

The Level-Cap is 10 in all difficulties, although one God allows you to go reach a few more levels.

There are two different bonuses: One for gaining levels and one for killing all monsters on a floor. You still receive the second bonus even if you are already at level 10.

It is grossly wasted then. Any chance of future patches to free this game?

The skill cap is part of the game design. you are not supposed to become the über-hero who kills every monster in an one-on-one. Instead, you have to use items and skills and monsters against each other.

You do have to escape some levels (floors) and sometimes the mouse overclicks on an exit and it is down before you can stop it, but considering that I reached Boss level on the third day playing and even got Balerio, in Nightmare mode, means the game is considerable shorter than expected despite its randomicity! I think the game admits many more levels, no character level cap, more graphical variety in the scene, more in-floor puzzles, etc. The reveal tile mechanic is truly remarkable and very relaxing.

I agree that this game has some issues, especially with the interface and language. And yes, it is quite short, winning it with one character even on chaos difficulty does not take too long. However, unlocking all characters, winning with all of them, unlocking all bonuses etc. does take some time. Some of the characters are actually quite difficult to play. I think the overall playtime is okay given the price, at least I did not expect more. However removing the level cap would need the developers to add much more content - currently there are neither items available that would benefit from that nor monsters that could still be a threat to a lvl20 character or so. I somehow doubt this will happen.

You can try endless mode, which you can activate with runewords. It seems to have endless dungeon levels. I don't know if the level cap is disabled there, though.