To get these collectibles, you need to beat the bosses and the enemies which come your way, and then you can collect these in the form of red star rings.
With a little toil, you can finish this part too and move to other challenges. These can take considerable time, but it isn’t impossible. There are certain collectibles in the game known as the red star rings, which can give you trouble to find, but if you do it diligently and start having fun while finding it, you are good to go. On average for someone who is good with the show and has his memory brushed up can complete the process of getting S rank within 25 hours, which is very little and will give you enough time to go onto other ranks.
In a Sonic Generation, if you have a good knowledge of the series, you can easily get the s rank, and that too exceptionally fast. Although the achievements we all try to collect in this version of the game are a lot and usually unachievable at max, finishing the game was a whole lot easier in modern Sonic. Two other “modern Sonic” games were released before the Sonic Generation came out and turned the tide for this new gaming era. Sonic Generation is a game that contains a highlight of the first-ever released Sonic Generation game, and you can relive all the old and nostalgic times with this.