Indoor soccer shoes can be viewed with three different styles which are futsal soccer shoes, street soccer shoes, and indoor soccer cleats. These three different styles of indoor shoes or flats can help in your search for a great pair of flat soccer shoes.
Indoor soccer cleats are a flat version of a Firm Ground soccer shoe. Using the same upper as the cleat version indoor shoes can add additional cushion under your heels or be lower to the ground with just a gum rubber non marking outsole.
Futsal soccer shoes like the Nike Elastico have their own style and you will not find it with a soccer cleat bottom. These shoes are light, bright and very low to the ground. This allows for ultimate ball control with all areas of your foot including the bottom. The requirements for a futsal shoe make it the most light and flexible indoor shoe.
Street soccer shoes like the Nike Bomba are tough and more durable for play on hard concrete and asphalt use. Again, you will not find a soccer cleat version of these shoes to wear on grass. These shoes are still very light and flexible but have some additional features that help with the durability of the shoe.