Score Bonus Calculation and Ranks

To calculate scores, Sonic Rush assigns points in categories at the end of a level. Contrary to almost all other Sonic games, points are not awarded within the level!

Acts award points in four categories, whereas Bosses award in only two. They are as follows:

-- Act Bonuses --

Time Bonus
Max: 85000
Each level has a particular time cutoff for 85000 points - for example, Leaf Storm 1's cutoff is 1:00. 5000 points are deducted after reaching the limit and every 10 seconds thereafter.

Trick Bonus
Max: 20000
Contrary to what might seem obvious, the numbers which appear when you perform tricks do not seem to count toward the bonus at all. Rather, ending a sequence with A, such as B B A off a spring, will award 1000pts. If you complete subsequent tricks in the same motion (eg. B B A U+R A), 1000pts will be awarded each time. Hitting the same widget again and tricking off of it won't net you anything. A successful trick can be recognized by the series of animals which pop off the bottom of the screen.

Ring Bonus
Max: 9990
The ring bonus is a straightforward 10x ring count.

Speed Bonus
Max: 10000
I'm not entirely certain what the Speed Bonus is, but suspect it is either average or (less likely) maximum velocity through the level. Things that can be ruled out are speed at the finish and amount of dashing.

So the maximum theoretical point total is 124990 - of course, that'll never be attained, since getting 999 rings is probably impossible and definitely impossible while maxing Time Bonus. Perhaps 120000 is achievable though...!

-- Boss Bonuses --
Time Bonus
Max: 48000
48000 points are awarded for meeting a target specific to the boss; 3000 points are deducted after that target and every 10 seconds thereafter. Similar to the Act bonus except in the starting and deduction points.

Ring Bonus
Max: Usually 6000,9000 or 12000
1000 points per ring held at the end. Rings are obviously far more important here than in the Acts, where they're only worth 10 each.

-- Ranks --

Every Act has the same rank benchmarks, which are halved for Bosses:

S: 100000 | 50000
A: 80000 | 40000
B: 40000 | 20000
C: Below 40000 | Below 20000

What does getting all S ranks get you? Well, I haven't gotten them myself, but I'm told it's a fat wallop of diddly.

-- Strategy --

Getting S ranks on Acts can seem impossible if you don't know how scores are calculated; but armed with that knowledge, the following method has tended to work pretty well for me.
1) Find the fastest route possible. (no small task!)
2) Determine the time cutoff for 85000 Time Bonus (the max)
3) Pull off as many tricks as you can along the fastest route while keeping within the Time Bonus limits.

Getting high Boss scores is pretty straightforward, and much more easily maxxed than the Acts. Just get all the Rings, keep them to the end and win as fast as possible. One consideration is that each time you get hit, your rings fly farther a-la Smash Bros, so if you get hit more than a few times they'll scatter to a degree where you won't be able to pick them all up again.