Honestly the idea of the game sound similar to Castle Crashers. Change up the idea a bit. Maybe instead of a bunch of different weapons you just upgrade your current one, by adding different things to it (IE Spinning Spikes, chains, sword on sword). But with the option to be able to buy spears, axes, and dildos. Just a thought. Don't rip right off Castle Crashers. Bring ORIGINALITY into the picture.
Plus you should practice art a lot more. Those drawings are too..bleh.