I like that your game fits the theme in multiple ways. At the same time, I think the stronger mechanic is creating loop shapes on the board, and the screen wrapping doesn't really add much. If anything, the scrolling camera makes it hard to predict where the next piece is going to spawn. This means I can't pre-calculate my inputs, which inhibits my ability to build muscle memory over time. In normal Tetris this usually isn't a problem because pieces always spawn in the same place, in the same orientation.
On the other hand, I think copying the full roster of 4-block shapes from Tetris maybe adds too much complexity on top of the multiple colors. Since you have multiple colors, I think it's ok to tone down the complexity in other aspects so that the player can focus on building the shapes they want. As it stands, even with just two colors, it's too hard to execute on a strategy IMO. I'd be very interested to see how this game would look with 3-block shapes, 2-block shapes, even single blocks, or only 2x2 boxes (like in Lumines), etc. Might be more manageable, and the player has some hope at improving, and maybe even build some chains?
Maybe a good reference point is Dr. Mario. In that game you have 2-block shapes, 3 distinct colors, and you have to make 4 in a row. That sounds super simple on paper, but it's complex enough to make the game a timeless classic. Compare that to your game which has 4-block shapes, 3 distinct colors, and you have to make a shape that is more complicated than 4 in a row.
Also IMO, if "loop" is the terminology we're using, I think it has to have a hole in the middle, whether that's a different color or empty space. This would add a type of friction that I think I like, because you have to be a bit more intentional about arranging your colors. It counters the strategy of grouping colors together, which seems to be kind of a natural thing for humans to do if you look across lots of different falling block games.
Very cool and inspiring idea, impressive implementation especially as a solo dev. Would love to see where you take it from here.