You will need at least 350 MB of free disk space to install Radium 2. Radium 2 system requirements state that you will need at least 512 MB of RAM. The cheapest graphics card you can play it on is an NVIDIA GeForce 6200. An Intel Core 2 Duo T7250 CPU is required at a minimum to run Radium 2.
Radium 2 will run on PC system with Windows 8 / 7 / Vista / XP and upwards. Additionally it has Mac and Linux versions.