1. You don't keep the coins you have collected already on a level when you die 2. Enemies shoot and spike out when you try to jump onto them 3. Levels are partly not reverse explorable if you miss some coins 4. In level 5 the platform moves too fast if you are supposed to collect all coins for the entire sequence. https://www.youtube.com/watch?v=0_DziYqDlu0 5. No chances to regain heart containers at important points, only at unimportant points 6. No continous playing, but just level select over the main m...