Well a big problem in this game is that no matter how high your DPS is, you still only beat levels so fast, cos it takes a considerable amount of time for enemies to actually come onto the screen to be killed. The stronger you get, the more obvious this becomes.

Many similar games allow the player more freedom in diving deeper into the run, IE, they only need to kill 1 creature per floor before moving on. This is certainly an option and something worth considering for CotLI, but my idea is a little bit different, as honestly I quite like the style of needing to clear each floor.

Allow the player to purchase a feature/option to play boss only for 1/4th their deepest floor.

Firstly, this actually encourages players to venture to a deep floor, something that doesn't really have too many incentives to do at the moment. Secondly, this gives the player a nice speed boost to skip the dull early levels, but doesn't make it too easy to get insanely fast resets.

1/4th is just a random number, devs could decide what is most balanced, or maybe even make the feature purchase upgradable (Ie, 100 idols = start at floor 5, 200 idols = 5,10,11..., 400 idols = 5,10,15,16... etc etc.) but still have some kind of max floor related cap.