I did it until Richter, its really easy until you reach him without gaining levels, I also didn1 used healing itens, only obrigatory items like the jewel of open (I entered Maria's Room to pick one of the rings without using Spike Breaker, but needed to use Fairy's bug, being the only place that I used a familiar or a healing item). But I used magics, I could do a Soul Steal with almost all my MP lol
Also, NEVER try to enter the corridor that leads to Chapel where you talk with Maria by the opposite side if you didn't meet she here yet, you will freeze your game, I did that using the wolf form to traverse the collapsing bridge and used medusas to reach high places in the clock tower.
Since it seems that another persons are interested in this type of thing apart of me, maybe I will recor my own version of this challenge in the future.