This is a game with very good presentation and an interesting idea but unfortunately its kinda brought down by the execution. Like the core mechanic of switching shapes is super cool but there's little reason to not use the square with its miniscule hit box (and frankly the circle is completely useless regardless of how you slice it).
I think with a rework of how the shapes work, this would be very good game; maybe instead of just changing stuff like speed you could completely change how each shape controls; for example the circle the circle could control like the standard Asteroids ship whereas the triangle has some sort of dash mechanic. I would definably be interested in seeing more :)