I suppose it was because I just became aware of the NES homebrew by Rigg'd Games / Lowtek Games -- "Chew Chew Mimic", that I wanted to pop in Chu Chu Rocket on the Dreamcast (released spring 2000 in North America).   I can't remember what year it was when I last dabbled with CCR.   So the game felt new to me, and I tried the 1-player puzzle mode.  The goal is to guide mice into rockets, avoiding cats if they exist on that stage.  You use the Dreamcast's 4 buttons to place  Up / Down / Left / Right arrows onto the grid, guiding the mice (and cats) when they cross the arrow's path.   On some stages, the arrows dissolve after about 3 hits from cats. 

At first it was all trial-and-error for me, but after a couple of won stages, I did start to see the board better and know to read the puzzles better.  I finally beat the 25 stages, which I haven't done in years.  I got a credits screen and Hard puzzles popped up. I beat those , got a credits screen, and Special puzzles showed up.  I beat 2 Special puzzle stages so far.    

I've read that Chu Chu Rocket was an experimental game to gauge how many 3D objects the Dreamcast could smoothly move and animate, and that this game there could be 100 simultaneously.  The game is super smooth and well animated. You click the Left Trigger to start movement, then can click it a 2nd time for speedier movement.  I was thankful for that, saves time while doing trial and error Arrow-placements.  

I never tried the online functionality back in the day, but my boys and I did create some new puzzles for each other to try.    Chu Chu Rocket is a fun puzzler, but I get my fill of it after a few days and it doesn't take too long to complete all the puzzles (or give up on some of them).  I'd rate the game  6/10, not a bad grade for such a simple concept that is fun for a while.