Technically two short films, Hulk vs. Wolverine and Hulk vs. Thor, with no attempt at connecting the two at all, which is probably for the best. There's also not much more to say for these; both shorts are just fight sequences with vague plots in place to allow for them to occur. The Wolverine plot line is more fleshed out, factoring in the Weapon X program as a reason for Hulk's rampage in the Canadian south, but it still largely feels forced. It also makes little sense that Wolverine has no idea who Hulk is, despite the briefing from the Canadian government and the inclusion of characters like Deadpool and Lady Deathstrike which place it quite late in the normal Marvel continuity. The result is entertaining enough, with some nice moments of humour, particularly between Deadpool and Wolverine, but offers little real merit.
Thor's story is at least a little more unique, with Loki transporting Bruce Banner to Asgard during the Odin Sleep and separating him from the Hulk, allowing the monster to be unleashed utterly on Thor and the other Asgardian heroes. It appears to have been Loki's greatest success, with Thor all but killed had the Sorceress not intervened and most of the other heroes defeated but falls down by presenting very two-dimensional versions of the characters. Thor and Banner clearly know each other, yet Loki seems to have almost no understanding of humanity or the nature of the Hulk. There is a nice subplot regarding Banner's time in Hel where he gets to live the life he most desires, but even here the conclusion is simply more fighting.
The animation is noteworthy, with some great fight sequences and good voice acting, but ultimately there is little more here than fan fantasies with an over-the-top budget.