Remember that short, dark period in gaming history when they attempted to use actual videos of people to represent characters in the game? Well, I'm going to do it. I intend to create a platformer with main gameplay similar to Jazz Jackrabbit, but like Crime Wave in style and (to an extent) story. The characters/animations are going to be video and photos taken of people I know. Anyway, I'm excited about this as an experiment in game design. Because this will be a 2D game, all the game assets will be photographs when possible. I can see one major problem coming from a mile away: With photographs for all of the backdrops, it may be very difficult for players to understand what parts of the level are passable or not (Can I jump on this dumpster? Can I open this door?) Any comments on the idea? What possible problems do you see with this basic approach to art assets--considering both resulting gameplay and asset creation/implementation?

try blurring thing that are suppose to be in the background, also though it will be difficult to take the pictures try at a bit of a angle to give more sense of deapth

Color is your friend. Obstacles should be set off with heavily saturated colors, or (in a pinch) by intensity that differs wildly from that of the backdrop. You might also consider multilayered scenery, such that the background is differentiated by a different scrolling speed.

Similarly to Sneftel, I would like to suggest one (or both) of two things:

1) Darken (or blur, or desaturate, or apply whatever filter best suits your piece or preference) parts of the background that are not interactive in some way - for instance, dumpsters that are not obstacles or platforms, or balls that the player can't pick up.

2) Use clear indicators, such as bright lights, to differentiate objects that are interactive.

I envisage this being particularly useful for objects not in the player's line of travel, such as doors adjacent to him that can otherwise be walked past to some degree. Simply, for instance, have a bright light on above a door that can be opened, but not others, or have some important symbol or word sprayed onto the relevant door.

This can also, of course, be used to highlight non-static objects, such as a ball that can be picked up, by placing them in such a way that they're more visible (such as putting such a ball under a street lamp at night.

Note that this can sometimes be done in post-production of the photographs, by overlaying other images or selectively altering features such as brightness and saturation.

Another idea might be editing the photographs to otherwise highlight important objects, such as by adding outlines.

As to potential problems, the first that comes to mind is that cropping sprites from photographs can be tricky at times, I think. I would recommend at least doing so against a background of solid colour, preferably one that is not present to any great degree in the appearance of the character or object. It might be a good idea to practise at it a little before starting in on sprites intended for your game. ^_^