Edit: There was a title update released recently that enables you to switch characters mid level so you can get all the collectibles and secret areas in one run through and by yourself. They have also lowered the requirement of timecores so now you only need 69 time cores to unlock all levels.South Park: Tenorman's Revenge Gets An Update
McDurbin and I made a video guide on how to get the collectibles and gold times on all levels. I'm posting on his behalf as he is banned from this site. I believe getting the collectibles will be easier playing with a friend. But depending on skill level it can be done solo, but it can take longer and will be more boring as you will have to play levels up to four times. You only need 120 time cores to unlock all levels so after we got 120 time cores we stopped showing where the time cores were. But McDurbin points them out as we pass them.
Credit to finding the collectibles and posting their locations goes to Jeesp on X360A. Here is his guide,http://www.xbox360achievements.org/forum/showthread.php?t=36
I won't post all of the videos as it will just take up alot of space. So below I will post the link to McDurbin's playlist and the video of how to get all of the megamen and secret areas on the first level, South Park 2546.
Here is the link to the playlist,http://www.youtube.com/playlist?list=PL5147499946EC3E40
And below is the video on how to get the megamen and secret areas on the first level