If you want to develop a game, you have to think first about the genre to develop the game for. Should it be a puzzle game / board game or an action game? After answering this question you have a lot of follow up questions to answer.
If you choose an action game (Jump&run) you have to take care of a lot more things than in a turn based game. You always have to take care that your programming is really performant, to achieve high frame rates. In a turn-based-game it’s less important as the user usually doesn’t notice if a calculation takes a little longer. A good overview on this topic is documented in this article, which is unfortunately only available in German language: Real Time vs Turn Based Games.
My first Android-Game-Project was such an Action Game. But the performance itself wasn’t the biggest problem for me (after I found some good 2d Game Engines). The biggest problem has been the level design, which take a large amount of time. That is why I postponed this project. After the start phase the level design took up about 80% of the development time.
(Graphics mainly from http://www.reinerstilesets.de/ – a really good source for grafics and more)