Retool system requirements state that you will need at least 4 GB of RAM. Additionally, the game developers recommend somewhere around 6 GB of RAM in your system. An Intel Pentium 4 2.00GHz CPU is required at a minimum to run Retool. You will need at least 2 GB of free disk space to install Retool. Provided that you have at least an NVIDIA GeForce 8500 GT graphics card you can play the game. But, according to the developers the recommended graphics card is an AMD Radeon HD 5450.
Retool will run on PC system with Windows 7 and upwards. Additionally it has Mac and Linux versions.