GOOD NEWS EVERYONE! I replicated your issue with same error and everything and found a solution! Cut and paste this into a notepad and save as whatever.bat
no error and launches every time ^_^ also sidenote I now own Stardew Valley <3 Damn you to hell :p

The issue was with the exe, since it has a space in it, it needs to be in "quotes" to launch.. give it a shot!

Edit: He had it before me... well you have the code now, enjoy your Windows 10 launching tile!

Great! Thanks a lot for the solutions (and for the funny remarks XD)!

Is there any reason why a regular batch command doesn't work for both games?

For the Spelunky it needs to be launched from the directory, some EXE's dont i tried it with a bunch of files... so you change the execution to the source and launch, this may have to do with 8.3 filenames (see below)

Stardew Valley is all because the EXE's name has a space.. in DOS there is no space and you cant have directories over a certain length.. it has to do with old school DOS eg 8.3 file names or short names

if your super curious hit up the link :)