Good retro classic: Actually, the title should read as follows: Sonic The Hedgehog 2 & Knuckles

As an old Sonic fan, I'm already pretty excited about the title. The game runs well, smoothly and quickly, as in anlten Megadrive times. Also the sound is right. Well I also like the layout, the choice of US / EU / JP cover of the original game, the different modes and options. Fantastic is also, which is Knuckles playable character. Thus, the game actually corresponds Sonic The Hedgehog 2 & Knuckles! So Sonic 2 with the additional module Sonic & Knuckles.
The thing that bothers me is the smartphone-related control. Although on-screen D-pad and button respond well and can be changed in size and transparency at will, but just missing the familiar touch panel. Never is really clearly expresses the direction in which, for example, the left thumb. It happens to me sometimes that Sonic running the Spin-Dash in the wrong direction. So constant monitoring of thumb is necessary with the view that distracts unnecessary, since the thumb anyway block a lot of the beautiful old graphics.