If you are playing on Steam, check out the Steam Community Guides for tips on the "To Court Death" achievement and other collectibles.

Your weapon has a battery. When it runs out, you must "recharge" it by shaking your controller (or mashing the assigned button).

Visit Ryan’s Gym to play mini-games that increase your strength and stamina.

The file you mentioned is a scene release for the PC port of the game.

For step-by-step boss strategies, GameFAQs hosts extensive text guides.