Metamorphosis: Titian 2012 invited artists from different disciplines, mainly the visual arts, dance and music, to respond to Titian's three magnifient paintings of the Diana and Actaeon myth. The results are displayed in an exhibition at the National Gallery (alongside Titian's originals), and in an triple bill of new ballets at the Royal Opera House. Each ballet has a brand new score, set and costume design by a distinguished contemporary artist, and multiple choreographers – some up-and-coming, some in-house reliable – as well as a handful of Royal Ballet principals to add star quality to the dancing.

It is hugely to Monica Mason's credit as outgoing director that she chose to focus so explicitly on new work for her last performances with the company. The collaborators gush in the programme notes about innovation and creativity, paying generous tribute to each other's ideas. Before the curtain goes up, advance publicity for this production suggests it will be a stunning affair, worthy to be the contribution of two heavyweight London institutions to the cultural olympiad.

And then the curtain goes up on Machina (Brandstrup/McGregor/Muhly/Shawcross), then on Trespass (Marriott/Wheeldon/Turnage/Wallinger), and finally on Diana and Actaeon (Scarlett/Tuckett/Watkins/Dove/Ofili/Middleton), and sadly hammers home three times the lesson that, sometimes, too many cooks spoil the broth. All three ballets have their individual merits, but none manages to triumph as a Gesamtkunswerk: by the end, I admired the ambition of the project, the prestige of the collaborators, and the apparently enormous budget of the Royal Opera House more than ever, but was far from being transported by the sublimity of the art.

Machina cast Diana as a seven-metre tall robot, whose light-tipped arm sometimes waved across the stage like a wand, and other times darted around and cowered like a paranoid eye. It was elegant, and I liked the juxtaposion of flesh and metal dancing, of organic and programmed performance, but unfortunately it distracted from the choreography more than complementing it. Carlos Acosta's first appearance, executing Wayne McGregor's trademark spinal undulation in silhouette, was probably his most powerful moment; otherwise his pas de deux with Leanne Benjamin failed to spark. Even the brooding Ed Watson and Tamara Rojo couldn't quite make their duet catch fire, spectacular dancers though they both are. In a complaint which became the refrain of the evening, the best choreography and the most exciting dancing were actually found in the corps de ballet sections, where two trios managed to capture some of McGregor's usual verve. I did enjoy Nico Muhly's layered, shimmering score, and Lucy Carter's lighting design was stunning, particularly when the robot was masked by a white screen, its light shining through from behind and gliding about like a rogue sun in wilful parabolas.

From its first moment, the choreography in Trespass felt tighter: eight male dancers progressed along a curvilinear trajectory in a series of tableaux, echoing the computer circuit designs on their costumes with long straight limbs which joined together like Meccano. Melissa Hamilton as the Diana figure repeatedly bent her body into a striking simulation of the moon/horns worn by the angry goddess in Titian's Diana and Actaeon, while Beatriz Stix-Brunell with Nehemiah Kish, and Sarah Lamb with Steven McRae, impressed the audience in their languidly gymnastic pas de deux. Mark Wallinger's giant curved mirror was the naffest part of the design, but his diamond-tessellated leotards for the women were my favourite costume of the night, and Mark-Anthony Turnage's tunefully percussive score was magical: Trespass came closest of the three works to creating a genuinely enchanting mythical space.

Diana and Actaeon had the odds loaded against it by being given three choreographers and an injunction to show the myth: perhaps predictably, this resulted in bitty, uninspired choreography and rather hammy storytelling. Chris Ofili as costume and set designer might have been a saving grace, but unfortunately his acid-coloured, cartoonish jungle and lurid leotards only made everything worse. Marianela Núñez and Federico Bonelli looked deeply uncomfortable as the title characters, and I didn't blame them – it takes a consummate level of professionalism even to try to dance like a Greek goddess while wearing a hideous orange wig. Diana's nymphs did better, in pastel-shaded unitards, and Liam Scarlett's neat patterning for them was refreshingly easy on the eye after Núñez and Bonelli's odd mime. Like the other elements, Jonathan Dove's sung score, which used Greek and Latin to tell the story, might have been alright alone, but in the context of this production it sounded melodramatic.

The Royal Ballet deserves enormous kudos for embarking on such an ambitious project. Unfortunately though, in this cultural olympiad it's still Titian and Ovid who romp home with gold.