An Intel Pentium 4 2.00GHz CPU is required at a minimum to run Cave Story+. However, the developers recommend a CPU greater or equal to an Intel Core Duo T2500 to play the game. In terms of game file size, you will need at least 200 MB of free disk space available. Cave Story+ system requirements state that you will need at least 128 MB of RAM. Additionally, the game developers recommend somewhere around 512 MB of RAM in your system. The cheapest graphics card you can play it on is an NVIDIA GeForce 6200.
Cave Story+ will run on PC system with Windows XP and upwards. Additionally it has a Linux version.