-Make a few more tiles (1-2 hours)
-Boss theme (1-5 hours)
-Apply tilesets to layouts (1 hour)
-Do 6 H animations (3-8 hours)
-Create the boss (3 hours)
-Add one weapon (half hour-hour and a half)
-One game mechanic (1-2 hours)
-Carry over save function (half hour-1 hour)
-Design remaining map sections for the first area (will take around 2-3 hours with testing)
You'll notice that there's a wide range of times, there. This is mostly because sometimes I'll do something like an H-animation, and finish it in an hour. Other times, I'll spend more time trying to get something right, or adding in additional animation that isn't really necessary, but raises the quality (like mounting animations or "cool down" animations)
I've got a timer app on my, phone, so I'll be timing myself for the heck of it. It will be interesting to see how far off my predictions will end up being -__-
As for the boss poll, I'll probably be doing another poll soon that will be voting between combinations of the highest voted elements.
Oh, and in case you were wondering what the game is like, it's a metroidvania, but with controls similar to the nes/snes castlevania games and a future setting. Health is increased by leveling up, but all other stats and attributes are raised through finding items. There are also some other mechanics involving stats that I won't mention here.