Just use plain C. Can't go wrong. You can draw on the experience you already have with C++ without having to worry about writing generic code, code generation, templates or classes and private and public stuff. More often than not, libraries that are out for C++ probably have vanilla C bindings (I know for sure SFML has this -- CSFML -- and SFML seems to be very good for writing games with).
In other words, try out plain C before trying to write a full game in C++. I feel like there's less obfuscation involved in C, and you can just get down to the meat of the code more easily than in C++. While C++ is by no means unreadable or unusable in my eyes, it feels... less so than C for projects that take advantage of the features C++ has to offer.