E3play_3 is a beta area in Pikmin left in the disc. It's also duplicated with the name play_3. This map may have showed up on an E3 Conference for people to play, or only for a trailer.
Gameplay footage
This area resembles both the Impact Site and the Forest of Hope. The only known way of playing on it is to replace files of existing levels, so the objects and music in the video are the same as in the first level of the released game. This also means the routes taken by Pikmin to return items to onions do not match those for the loaded level terrain, and they go the wrong way.
{{#ev:youtube|kl0pagZp6r4|500|play_3/E3play_3 is the first area shown in the video.}}
Geography
It has multiple routes, and lots of ledges and wooden platforms. There is a lot of fog in the background, similar to other beta levels. The ledges are similar to those in The Impact Site and The Forest of Hope. The grass is actually taken from the Forest of Hope, but is slightly darker.