Thanks for your comments, the feedback can really help my later development for the Post-Jam!
More efforts are definitely required to find a better physics implementation, the current one causes lots of weird bugs, introducing unpleasant experience. Fixing this is the FIRST thing on the TODO list.
For the portal, it teleports the avatar not when you step on it, but when you leave it, which is kind of a special flavor or twist for the game. In this part, I set a design principle "Half-predictable". Most of the time, I want the player to be able to infer where the portal goes based on the hints from color and edge direction. On some occasions, the portals can lead to strange places, where the player can start a new adventure, but which also would be turned out to be closely connected in the whole map. In later development, I would also improve the level design part.
Thanks again for your time, and hope I can publish a better version later!