codetoeternity 0 Newbie Poster

hello dear people. i plan to develop a game. replicating jetpack joyride. i wanna use c++ as primary language. i think i have two options. 1 is directx and other is cryengine (correct me if there are other c++ options) . at current i dont have knowledge of either directx or cryengine. so first i'll be learning whichever i'll choose. i wanna know, which one is better choice for a career in game programming? i also wanna have an idea if i will be able to complete the learning and development in 7months (with full attention).
thanks.