How does the rotation work?
It's a lot of sprites. It's much faster to move around sprites than to try rendering a rotated field in the background. The downside is that the sprite limits get in the way, which is why the visible area is restricted and scenery is so sparse.
Sprites usually come in steps of 11.25°, but large objects (including walls) are made out of multiple sprites that move independently and hence it looks much smoother.
How much space does voice acting take up?
Around 800KB. There's around 76 seconds worth of voice acting, however the game uses a system where cutscenes are built out of multiple sub-phrases that are strung together, so the total scenes add up to much longer.
Voices are stored uncompressed (raw 8-bit) at 10650Hz. They could have been compressed, but there's a lot of free ROM space and it wasn't worth risking to break the sound driver.
Does it work with Sonic & Knuckles?
The diagonals don't work!
Don't use Gens with an XInput controller under Windows 10. Other emulators should work fine.
What's the Mode button?
It's a button present in most 6-button controllers. Depending on the model, it's either the right "shoulder" button (where R would be) or in the middle (next to the Start button).
Some clone 6-button controllers lack a Mode button. You can still access the map by pausing the game and selecting it with the D-pad.
Do I need the keyboard to play with the mouse?
No, you can use it together with a controller too.
The keyboard/mouse doesn't work with my Mega Sg.
Enable Passthrough Mode in the system settings.
How do I connect the keyboard?
Arkagis Revolution supports the Saturn keyboard (or the NetLink keyboard adapter), but the plug shape is different than what the Mega Drive takes. In order to use the keyboard you need to get a passive adapter that takes a Saturn controller and has a Mega Drive plug on the other side.
If you want to build your own adapter, you can check the controller pinouts at Plutiedev (connect the lines with the same names on both sides of the cable).
How do I use the keyboard in an emulator?
As of writing, only BlastEm supports the Saturn keyboard. Press Esc to open the menu, then go to Settings, System, IO Port 1 Device and select Saturn Keyboard (you may as well also set the mouse in port 2).
To use the keyboard, press the right Ctrl key to "capture" the keyboard (press it again when you want to use BlastEm's shortcuts). If it doesn't work, quit the emulator and reopen it.
Remember to change it back before playing another game!