Okay
This game has a good concept, but it just fails in 1 aspect.
When you hit the obstacles, you will get slower, but sometimes, since they are randomly generated, you have no choice but to hit them - otherwise if you jump, you will land in the wrong spot and fall of the building, resulting in game over.
If you don't jump, it will slow you down and you won't have enough speed to jump over to the next roof.
This is just frustrating. Otherwise I would give it 9/10
The game is so simple, so I don't see why it should have any issues at all.
Also - a little scenery change and having actual goal never made a game bad. Adding variety to the gameplay is IMHO key to success.
For those that like to challenge themselves, there could be freeplay mode.
This is not why I gave it 7 - just an advice, if you want to make a WOW! game, instead of a game that you forget after 15 minutes, even if it was good.
Otherwise the style and visuals were very good...