I've spent several hours working on a new method to remove the possibility of abusing momentum with two portals on the ground. This new method is much more robust, taking into account the history of entry and exit from the portals, thus preventing gaining a lot of velocity by moving from one ground portal to another. This will prevent skipping puzzles or leaving the map.
I also fixed a minor issue in the introduction where a portal could sometimes be placed slightly into the scenery.
I corrected an issue where old portals were not being removed when moving to a new puzzle.
I made modifications/corrections to Room 15 following changes to the jumping system; the puzzle remains the same, just with some adjustments :)
An "edit preset" button has been added to the game's graphic settings to easily edit a preset of settings.