Is there any way to set the folder where tic files are saved on start up? Instead of the default "C:\Users\DePingus\AppData\Roaming\com.nesbox.tic\TIC-80", it would be more convenient (for me at least) to have that folder reside on a USB drive so I can work from different computers. PICO-8 has the -home command line argument that does this. Speaking of which, some more startup command line arguments would be nice too; like -width, -height, -windowed.

I can't give this dev enough praise. This feature has been added as of version 0.50.1

Start the program with "tic80 ." (yes that's tic80 space dot) to use the current directory.

btw (i don’t know if it is the same situation), when we open a .tic file somewhere, it creates a ./.local/ folder in the same directory - wasn’t supposed that tic80 would create and/or use something like ~/.local/share/tic80/ instead?

To get rid of the cmdline popup in windows, you could also opt for this script and name it RUN_TIC80.vbs (again, be aware of the space before the final dot on commandline. Also, place this script in the same dir as tic80.exe):

Set oShell = CreateObject ("Wscript.Shell") 
Dim strArgs
strArgs = "cmd /c tic80 ."
oShell.Run strArgs, 0, false

Nevermind the param error popup that follows when starting up. The dev already fixed that issue and will be solved in the 0.70.+ release of Tic80. 

Thanks a lot for this topic, I had the same issue (wanted to use TIC-80 in portable mode on a USB key too), and I found the solution thanks to you!