Teams are definitely allowed
I honestly don't know what you mean by which platform, you can make a game for any platform, but those for consoles are probably gonna get less play and are going to be more difficult to make
This game was so strange, the hitting of the coins felt really inconsistent and at the beginning I had no idea when the hit on the red bombs counted.
The idea of throwing a coin that you can then hit to gain a boost is really interesting, but I needed to stop all my momentum to hit it well, and that meant that at a lot of points i had to either jump a couple of times or hope to dear god that i can hit that coin.