UPDATE #5
Another week bring us right into the start of autumn, that is one of the seasons featured in the game, as both characters are split by space and time, while one lives in spring, the other stands at the doors of autumn, allowing us to play with different settings and different colors schemas in the game. Development has not been straight forward because a couple of bugs with the boxes and the jump, that we thought were fixed, reappeared in different cases but with the same overall result of blocking the progression or, in the case of the jump, block or allowing to overcome most of the puzzles. We have worked hard in discovering the reasons why the solutions that we applied in the previous build were not working, and we think that we are heading in the right way. We have been also fine tuning some mechanics as to integrate it more consistently in the gameplay without creating a dissonance Added:
-Linked the box reset mechanism to the paper life bar. This makes that every time the players uses the box reset the life/energy bar will decrease forcing to have a strategic view on how much time resets should be performed versus the  level of dangers and enemies that will have to be faced through level.
-Linked the Stealth mechanic to the paper life/energy bar. Similar to the box reset mechanism, but in this case only applied to Princess Keiko, which in the previous versions could basically stay for ever in stealth which allowed her to unnoticed with the enemies. We think that this was affecting the overall game for the character and though that since it is a mechanism that can be used to gain an advantage over the enemies, it should  be consuming paper as all other power ups or combos in the game. This will make the character more interesting to play with while in stealth, as it will be affecting directly the possibility to perform further origami actions or to take damage against other enemies.
-Coop. Not yet enabled, but we have been working on the new UI and menus that will deal with the new game flow and we are currently making some testing on the different combinations of controls allowed for the game as players play with the different characters. Fixed: -Grab Box. We have fine tuned the box grabbing feature, making it working in a smaller distance to the box, to avoid the possibility of grabbing and pushing the box. - Jump frame speed dependency. We thought that we had solved this problem, but apparently from some feedback that we have received, not yet totally, so we have been making some more adjustments as to be as consistent as possible.
- Yet Another Performance. As always, performance is at the heart of our work, trying to stabilize the framerate as high as possible. We have been working in avoid the much threaded Garbage Collector ( the nightmare of Unity games) and we have improved the stream functionality of the systems that are disabling everything that is not seen in the game. As always any feedback on the discussion board or by email is greatly welcomed as it allows us to keep improving the game and cleaning it from bugs that sometimes we were not able to spot correctly, or to check on fixes that failed to solve them. Also we are open to suggestions or requests that could help us make the game even better. Upside-Down Forums Thanks for playing our game and  Stay tuned...