Hi, I'd like to make a game of this style:

Here's a vid of some guy speed running the game:

-Puzzles

-Turn based combat

-Sort of 2d - There is most definitely floors/stairs/object height etc but nothing like a true 3d game

I'm pretty indifferent to the platforms this will be played on, but PC or android would be preferable.

I'd also like to be coding the game -- not just using a game-making program.

I am well-versed in C, so I can easily pick up C++ and C#, from what I've read I think C# would be great to learn. I've written some games in C (pong, text-based adventure games, snake) etc, but I'd like to start making some more real stuff. I thought about making ASCII art based games but I'd need to zoom the command window out extremely far and have an absurd amount of symbols to make anything of decent quality.

Thanks in advance!

There's no such thing as "best." Literally almost any game engine/language would work. Pick one you like and go.

As Sean said, no such thing as 'best'. If you go for C++, use SDL. If you go for C#, use Monogame. Also, this is gonna need a LOT of art...And time. So you'll either need a person to get on board, hire an artist, or learn 2D art.

C++ and SDL, got it.

Really hope my future CS courses switch from C to C++

If you are learning/know C...that is good enough to get going. SDL is c-style library, so no compatibility issues or weird features

C++ and SDL, got it.

Really hope my future CS courses switch from C to C++

Don't worry. It will. Though it's probably not going to be as fast as you'd hope. Play around with SDL for a bit. It might help first to build some tools.

If you are learning/know C...that is good enough to get going. SDL is c-style library, so no compatibility issues or weird features

I second this. SDL is actually written in C. So you could actually start right now. C++ is just C...with extra features and classes. I suppose that's why it's preferred for game development. C-compatible code is still necessary to use many SDL functions (example).

As people stated, there are some libraries that have better tools to help you.

I am personally a fan of ORX, which also a C engine and is data-oriented. It uses ini files to describe objects making changing things in you game much easier. It also support graphic effects* and particle effects, which is a great addition.

If you are willing to use python you can also use Pygame, which can be seen as a SDL adaptation for python. The main advantage (besides using a higher level programming language) is that there are literally thousands of code snippets that you can use.

* Basically a variation of one attribute of an object, for instance the classic monster blinking before dying is a variation of the alpha of the monster.

If you consider portability for future, as in maybe one day wanting to code your game to mobile phones as well, Cocos2d-x might be a good choice as well, although SDL does support quite variety of systems. I think Cocos is a bit higher level than SDL, as I think that Cocos2d-x is a game engine, where as I consider SDL more of a framework. Also it has some tools for UI + rather big community. It does have it's own learning curve though.