This is a really good take on the theme gameplay wise. I liked having the ease of upgrading to get a glimpse of the end, just to get demolished- then avoiding upgrades to make the end easier. This ebb and flow with difficulty is a very inspiring take to challenge, and I love it! Having no music fit the game nicely, kinda like a samurai showdown. My only gripe is that I wish blocking was mapped to the right mouse click, and that some of the sprites quality were improved. Again, I really like your approach to challenge!