SYSTEMS AND METHODS TO DEFINE A CREATIVE ASSET FOR PRESENTATION WITH STREAMING VIDEO CONTENT THROUGH DIFFERENT VERSIONS OF A STREAMING VIDEO PLAYER APPLICATION

1. A system configured to generate creative asset files for rendering creative assets with streaming video content through different versions of a streaming video player application, the system comprising: one or more processors configured by machine-readable instructions to: receive, from a user via a design user interface, an arrangement of items of content for a creative asset, wherein the creative asset is media for presentation with streaming video; determine a creative asset specification that conveys the arrangement of the items of content, wherein the creative asset specification includes at least: a creative asset type for the creative asset, and, for individual ones of the items of content, parameter values for a set of item parameters, and wherein subsets of parameter values for the item parameters are compatible with different versions of a streaming video player application; analyze the creative asset specification to verify that the creative asset specification is compliant with a player-compliant schema for encoding media; generate a creative asset file that facilitates rendering of the creative asset by the different versions of the streaming video player application for presentation with streaming video, wherein the creative asset file conforms to the player-compliant schema, wherein the creative asset file represents (i) the arrangement of items as a hierarchy of objects in which the creative asset as a whole is represented as an asset object at a highest level of the hierarchy and the individual items included in the creative asset are represented as item objects underneath and (ii) the asset object, wherein the item objects specify the parameter values for the item parameters from the creative asset; store the creative asset file to electronic storage media; generate multiple renderings of the creative asset from the creative asset file that reflect expected renderings to be generated by the different versions of the streaming video player application, wherein the different versions of the streaming video player application include a first version and a second version, and the multiple renderings of the creative asset include a first rendering that reflects an expected rendering of the creative asset by the first version of the streaming video application and a second rendering that reflects an expected rendering of the creative asset by the second version of the streaming video application; and effectuate presentation of the multiple renderings through the design user interface so that the creative asset is preliminarily viewable by the user as it is expected to be rendered by the different versions of the streaming video player application for presentation with streaming video. || 11. A system configured to implement media guides in accordance with different versions of a streaming video player application for rendering creative assets for presentation during streaming of video content, the system comprising: electronic storage that stores individual creative asset files that facilitate rendering of individual creative assets by different versions of the streaming video player application for presentation with streaming video, wherein the creative asset files conform to the player-compliant schema, wherein a creative asset file represents (i) an arrangement of items of content as a hierarchy of objects in which a creative asset as a whole is represented as an asset object at a highest level of the hierarchy and the individual items included in the creative asset are represented as item objects underneath and (ii) the asset object, wherein the item objects specify the parameter values for the item parameters from the creative asset; and one or more processors configured by machine-readable instructions to: receive a media guide that outlines presentation of the creative assets during a stream of video content through different versions of a streaming video player application, wherein the media guide includes: (i) temporal markers within a duration of the stream at which the creative assets are permitted for presentation, (ii) reference to one or more of the creative asset files utilized to render one or more of the creative assets, (iii) instructions for selecting one of the one or more objects to be rendered for individual ones of the temporal markers, wherein the instructions are based on at least consumer information and the streaming video player application, (iv) playback-updates that cause modifications to the stream responsive to interaction by consumers with individual ones of the items, wherein the playback-updates are associated with the individual items, and (v) asset presentation updates that cause modifications to presentation of the creative assets responsive to stream modifications imposed by the consumers; determine a version of the streaming video player application that the video content is to be streamed on; and implement the media guide in accordance with the version to cause rendering of the creative assets by utilizing the subsets of the parameter values in the one or more creative asset files that are compatible with the determined version. || 15. A system configured to render presentations of creative assets within streams of video content through different versions of a streaming video player using creative asset files that conform to player-compliant schemas, the system comprising: one or more processors configured by machine-readable instructions to: store individual creative asset files that facilitate rendering of individual creative assets by different versions of the streaming video player application for presentation with streaming video, wherein the creative asset files conform to the player-compliant schema, wherein a creative asset file represents (i) an arrangement of items of content as a hierarchy of objects in which a creative asset as a whole is represented as an asset object at a highest level of the hierarchy and the individual items included in the creative asset are represented as item objects underneath, and (ii) the asset object, wherein the item objects specify the parameter values for the item parameters from the creative asset; and receive, in an ongoing manner from individual players executing the different versions of the streaming video player application, individual requests for individual creative asset files to cause presentation of the individual corresponding creative assets on the players, wherein the requests are in accordance with a media guide that outlines presentation of the creative assets during a stream of video content through the different versions of the streaming video player application on the players; and effectuate, responsive to the individual requests, transmission of the individual creative asset files to the players to enable rendering and presentation of the individual corresponding creative assets on the player.