The game is officially available for PC via Steam . You can purchase it directly from the Steam Store to get the full version, which includes Steam Achievements and Cloud Save support.
While Rose is fragile, the Giant is immune to most hazards. He can carry Rose, throw her to high ledges, and move massive objects that are too heavy for her to budge.
Rose can absorb "blood" (color) from objects to freeze them in time or give it back to static objects to set them in motion. This manipulation of life and stasis is key to bypassing obstacles.