Cave Story/DSiWare
This is a sub-page of Cave Story.
The second official port of Cave Story, and the first on a handheld. While it's a little buggy in terms of music playback and lacking most features found in the Nicalis ports (though it was the first to contain the Jukebox), it has a few interesting quirks of its own.
Build Time
In the main folder there's a .txt file named 'buid_time', containing the build date:
build at 2010/10/10 14:48:07 on "Simon-PC"
'Simon' is probably Simon Parzer, who is listed in the credits as 'Lead Porting Programmer'.
Unique Content
Though this port's uniqueness arguably stems more from its lack of features rather than unique ones, it does have a few things worth talking about.
Sanctuary Image
The Sanctuary Time Attack mode is the only challenge that this port contains, and beating it nets you this artwork - this is seen again in the 3DS eShop ports.
Misery's Portraits
Misery's portraits have their correct hair colour, despite the DSi port using freeware assets - while the Nicalis upscale fixed her hair colour, they tend to leave the freeware assets alone, making this the only version to have Misery's original portraits colour-corrected (the eShop version does technically have 1x resolution blue-hair Misery, but that uses a downscaled version of the CS+ portraits).