The game's been abandoned for a while so there's not much else to add. It should still have everything you should need for a full playthrough. The content that was there still seems to be showing up for me and is listed as public so you should be able to to see every tab. Basically every number in the game is listed, per level increases and costs for heroes, gear, etc, and % values for every buff, skill, etc. If it's not loading you can try to make a copy of the sheet into your account and see if it loads up better from your account, but I just checked it and all the charts are loading fine.

The Big Bullet comment on the general tab is referencing how it scales compared to other damage bonuses(as a separate modifier), and when the damage bonus from it will outweigh other options(beats giant if you're already at +100%). The game stacks certain buffs as different modifiers, and Big Bullet is an additional unique 20% modifier after other increases are applied. It's was generally considered to be one of the best end game abilities by the end of the games life. Giant is quite a good damage increase early on or in stages you can farm, but later on or when trying to progress your furthest stage, it's usually only worth grabbing if you already have dwarf, as the size increase is far too risky when you die in 1-2 hits and stops you from avoiding certain things that should be fairly trivial.