Imagine Tiny Wings terrains (slopes and hills) and control (touch to get down to the ground and gain speed on the slopes, release touch at uphills to let your character fly) combined with obstacles à la Jetpack Joyride. Obstacles won't be exactly same as from Jetpack Joyride but as an example, maybe bombs in the air or shooting lasers (in Jetpack Joyride, they use missiles).
I haven't prototyped the game yet, but I sense two problems here.
Problem 1. Obstacles become much harder to avoid as the only control you have over your character's movement is touch to get down to the ground when you want. (think Tiny Wings) You cannot jump at will.
Problem 2. Above problem might be able solved by clever level design by placing obstacles at certain points to provide some challenge but not extreme difficulty. But since the game is an endless runner, designing a placement of each obstacles and terrain is almost impossible or rather oxymoron. Plus anytime the game is played, the obstacles, terrain everything will be the same. This takes away the fun. I contemplated making the terrain flat and give the character ability to jump at will, but decided against it as I want to explore other possibilities.
What do you guys think? I am open to any suggestions.