Just tried your game and well, i felt a bit lost and i didn't even understand what i had to do ... I went into random portals without any clue on what i was doing, and when the timer went out i just ended up swimming to the edge of the map, and finally quitting.
There is a real performance issue though, and i think this is only due to the grass.
However, i really like the chill atmosphere of your game !
Keep it up !