Sonic CD
12 Achievements
200
8-10h
88 Miles per Hour
Travel through time
5
How to unlock the 88 Miles per Hour achievement in Sonic CD - Definitive Guide
Being at speed when seeing this sign is not the issue, but not stopping as soon as you did is the most diffecult. Use those red jump springs to keep the speed going. You can better jump one time to many then one to short.
This achievement can be taken in each level. Good Luck!
Video for visual reference. It's not mine - i take no credit.
You'll know that you are at the required speed when you see a trail of stars as you are running. If you keep it going long enough, you'll see the screen change and Sonic will fly up on a green looking background. The achievement will unlock at that time.
I highly recommend going to the "PAST" FIRST as you will need to be in the past for certain other achievements as well, such as "Paradise Found" and "Saviour of the Planet".
You can get this achievement on any Zone 1 or Zone 2 level in the game. The easiest way I've discovered to get this achievement is to find a past sign on a level, and then to find a vertical yellow or red bumper. Enter the spin dash attack mode by holding +. When you spin dash, you automatically enter the time travel mode. You will know this is happening because Sonic will be surrounded by a shimmering force field. Spin dash onto one of the vertical bumpers and just bounce up and down until you travel through time.
Simply run past a “Future” or “Past” time post and find a place where you can gain a lot of speed (loops or springs that go back and forth). This will cause sparkles of light to form around Sonic. Once Sonic disappears that means you have traveled through time. If you get stopped by something and the sign post to the left of your life count is blinking that means that you are about to lose the ability to time travel. This will pop up during the time travel sequence. NOTE: Technically this achievement is missable but I’d find it hard to miss unless you deliberately do so.