Somewhere at the intersection of Super Mario World/Galaxy, Katamari Damacy and a pro-environmentalism PSA lies Gomi HD, currently one of the few platformers available for the iPad. Since the original Gomi for the iPhone has already been reviewed, I'd advise you to read that review first before proceeding with mine, as the original has a far more comprehensive overview of the game's background and gameplay.
All done? Great! I would love to tell you that Gomi HD represents a significant step ahead for the retro-indie game, and that every aspect from gameplay to graphics has been overhauled and enhanced. Alas, that is not the case. Gomi HD is nothing more than the original iPhone game with moderately enhanced graphics - emphasis on moderately. If you've played Gomi, you know it's not a graphical powerhouse to begin with, so you shouldn't expect more from this new version than brighter/sharper colors and graphics that are a bit more defined.
At its core, this is the same old Gomi. You are a circular character who rolls and jumps from world to world, consuming societal refuse along the way and leaving pretty flowers in your wake. I can't argue with the message, and I suppose this could be a fun kids' game, but for an iPad game it's woefully lacking in graphical prowess. Take the main character Gomi for instance. Since he's eating all manner of junk along his travels, it would be nice to see him dynamically change/grow/morph as he merrily rolls along. Instead, things stick to him, but they seem to have little impact on the character itself (is Gomi male? Female? I can't tell!). Movement is sluggish, and jumping is created by tapping the screen. This works fine, but I just kept waiting for an option to speed up Gomi's movements, even if only briefly.
Yes, Gomi HD is one of a very select group of platformer games currently available for the iPad, but that should not encourage you to go ahead and spend your money. If you already have it for the iPhone (where I can see this game being much, much more effective) then you would be best served to just keep it there. The iPad is bound to get some more polished platformers in the near future, so my suggestion is to just wait it out.
I don't see paying $4.99 for a game that should simply be bundled with the original Gomi as a universal edition. Raise the price of the original Gomi if need be ($2.99 to $3.99 or so), but don't charge twice for the same game on two very, very similar platforms. Gomi HD is a moderately clever game, but not clever enough to justify two separate purchases.