When it comes to Inkling for me the biggest hurdle is the sheer number of characters. You could argue that it's a syllable-based alphabet like Japanese which would make sense given the game's origin, but it doesn't answer why the logo for the in-game brand Forge has so many characters making up its name.
It's entirely possible that Inking uses a phonetic alphabet similar to IPA. This would allow a much greater number of potential characters which correlates well with what is seen in the game, but it still doesn't answer everything. It is also possible that Inkling has several alphabets for different situations, which is unlikely but not impossible (as well as impractical).
It is also worth pointing out that the Squid Sisters vid from the Direct is subbed in Inkling:
This not only shows that Inkling has word boundaries unlike many Asian languages, but also that the character strings range in length enormously. Some of what appear to be multiple words when sung are subbed as being single strings, suggesting that it's common for compound nouns to be presented as single words in a similar fashion to Modern German.
Another note to take from this video is that the first line of the song is nearly identical to the text that appears above 'Squid Sisters' just moments beforehand. The first two strings are identical, and considering the subs supposedly say 'Squid Sisters' in Inkling, it's possible that Inkling may use some form of reduplication for plurality, and that this word is 'squid' or 'sister'. If this is true it would also indicate that noun order is reversed compared to English (where the head of the compound noun occurs at the end), and would likely mean that Inkling is a largely post-modifying language as opposed to pre-modifying.
This isn't particularly in depth at all but I thought I'd slap some info out there!