From my personal experience, the two main challenges when it comes to making video games are:
1) It's a multidisciplinary effort. Unless you're someone with multiple talents, you need to put together a team to work on it. You might try to pull it off all by yourself using free resources you can find on the Internet, but it's next to impossible to make a truly great game that way.
2) The biggest amount of work will be spent on "polishing" things. Dotting the i's and crossing the t's, testing your levels and tweaking them, all that stuff is a lot of work. And videogame players are a lot less forgiving than other application users.
1) It's a multidisciplinary effort. Unless you're someone with multiple talents, you need to put together a team to work on it. You might try to pull it off all by yourself using free resources you can find on the Internet, but it's next to impossible to make a truly great game that way.
2) The biggest amount of work will be spent on "polishing" things. Dotting the i's and crossing the t's, testing your levels and tweaking them, all that stuff is a lot of work. And videogame players are a lot less forgiving than other application users.