I am happy to hear that you're continouing the development of the game!
Yeah i am pretty excited to see the survival mode :D, all the blood effects would make it look really cool.
Also are you planning on a LAN mode any time soon? I would love to play with my friends sometimes Maybe even a 2v2 where you have 2 planes of duels (As in, it would be the same way as it is now, but 2 different depths on the screen). I know it's a bit hard to implement, especially i have no idea how it would be done in GameMaker (since i use Unity myself, previously used GameMaker a bit)