It would be nice if the world looped itself instead of just stopping, Also... You should switch the vibration upgrade with a machine that can change the amount of vibration that it makes and every time you upgrade it you can make it make more or less vibrations, Also... The ending is kinda left out, You should either make a sequel or expand it. Last thing... you dont have to do this i just want to give my 2 cent like everyone else does....
Thing about games like this though...: They run out of updates and start to decline in popularity... And then everyone just forgets about it...Then it is dug up by some determined player and it is called 'An Old Legend'...