I was a huge fan of last year's Osmo Creative Kit with Monster Game, and if you didn't pick it up, I still highly recommend it for Holiday 2017. However, this new offering, Osmo Coding Jam ($59.99 without base or tablet, both required) leaves me cold.
Like many other musical programs, this one is a kind of sequencer. Magnetic tiles read by the Osmo tell an avatar whether to play the "instruments" above, below or to his sides. The color of the tiles direct whether to play in the first, second, or third ring that surround the musician.
The tiles link together to form a sequence of instructions. Additionally, you can add tiles that cause parts of the "program" to loop. There are a variety of avatars, each with their own instruments.
If I rate this set as a musical program, it just isn't too "musical", the sound being less melodious and more "noise maker". If I rate it as a "cause and effect" machine, it is not always particularly clear what sound is being produced for which bit of code. The instrumentation and tune represented by a given tile is not always well differentiated.
Osmo's older Coding with Awbie ($42.99) set uses a similar tile set with clearer goals that demonstrate cause and effect in a much more direct way. The object in that set is to move a character in a maze-like environment using only the program tiles.
Parents looking for a similar sequencing toy might consider Nuerosmith's Musical Blocks ($62). There, five cubes are placed in a row, each of which can play one of six snippets of Jazz, African rhythms, and even a bit of Mozart.