Subjectivity, not always a bad thing as this game might just be for you.
Bear in mind though that, if you don't like Van Halen or semi-older rock in general, this game won't be your cup of tea.
If you like older Rock, Van Halen, rocking out on a plastic guitar and having a blast with your friends, then I can really recommend this game.
As with most other Guitar Hero games, it is clear that the tracks were meant to be played on a higher difficulty than Easy. Sure, you can rock every song and play them almost flawlessly, but the fun lies in the challenge, in besting a song and making it your own, and GH:VH manages to do that almost perfectly on Medium and Hard, I dare say, even Expert has its moments. The song structures are balanced overall, though there is a lapse in reason every so often, where songs seem to have been made more difficult than necessary, but those moments are rare and far in between. You will probably spend most of your time enjoying yourself, maybe even grinning from ear to ear as the guitar in your hand makes you feel like a rock star as you rock your way through the game.
The game is not without flaws in all honesty. The track list is a bit lacking, clocking in at only 44 songs, you may end up blasting through this game in a day on the lower difficulty settings. The visuals also feel a bit dated now that there are newer versions of Guitar Hero available.
To conclude, Guitar Hero: Van Halen is worthy of consideration if you are a fan of the series, hope to expand your track list or plan on playing this with your friends, and it offers a good amount of pleasure if you let it.
So get your rock on!