The minimum OS requirement for TF FF is Android 4.4 (Kit Kat) and at least 1 GB RAM should be installed on your device before installing the game. Although it may not seem like much, please keep in mind that you will be fighting intense battles with hundreds of enemies at the same time. Installing a RAM expander will most likely leave you overpowered which means that your device will not last long against the most challenging Transformers.