Yeah, I'm going to fix the crashing after the game jam. I had to remove some files to get the game to be small enough. You can totally make it to the end without buying any items. At level seven, you should be able to beat the boss without any items. If you really wanted a challenge, you could try going low level by running from everything, but I don't suggest that unless you are at least level three by the time you get to the tower, since in my testing with my playtester, that was the lowest level they were able to beat the golems on.