For a brief, simple, and graphical precis, see Guide:Game Progression graph.
This page attempts to summarize the game development, in textual content shape. It will deliver hints for manage of the transitions in the game, and note key gadgets to craft or discover (beyond the next tier of guns and armor). Some hints will represent opportunities for "sequence breaking", via gaining equipment slightly earlier of the "typical" timing. For a greater specified and images-heavy manual, see the Walkthrough Guide. For details about strategies for every particular boss combat and/or occasion at a sure point in development, see their respective publications.
