We have been working on this game jam for 2 or so weeks now. We started with another game jam game since the rules allow for participants to use an existing game. With the titan boss theme we went big. The boss is 4+ screens tall and about 30x taller than the player. You need to scale up a procedural generated vertical level while the boss punches through walls to get at the player. While you do have a gun, the gun only defends against the arms coming through walls and you need to get the boss to punch itself in the face over-and-over again. When the boss takes damage it goes lower through the level with its head obliterating platforms on its way to the bottom.
Not to spam the game or anything, here it is: https://sitebender.itch.io/cake-kills-candy
For anyone that just wants to skip to the boss, I have a cheat console when you hold Ctrl + tab. Then type in "baws" and that will send you to the boss. Otherwise the boss is at levels 11, 21, 31 and so on. I wish that there was a way to explain this on the game jam page for the game because this information is specific to this jam. I tried putting this in the jam comments for the game, but there was a 1024 character limit and as you can tell I am wordy :-)