Blue-chip non-fungible token (NFT) brand Azuki released the latest expansion of its NFT ecosystem on Tuesday, raking in $38 million in 15 minutes.

Azuki “Elementals” was first teased last week at a holders-only event held in Las Vegas titled “Follow the Rabbit.” A portion of the 20,000 NFTs, which are based on the four Azuki elements of earth, fire, lightning and water, were airdropped to holders.

The remaining NFTs were available for purchase beginning on Tuesday at 9 a.m. PT. Holders of Azuki NFTs were given a 10-minute presale minting window while holders of BEANZ – a derivative project – were given presale access 10 minutes after that. At 9:20 a.m. PT, a public sale was meant to commence.

To participate in the presale, Azuki and BEANZ holders were required to put down a deposit of 2 ETH. The entire collection sold out within 15 minutes, eliminating the need for a public sale.

According to data from Etherscan, the wallet address that holds the Elementals mint funds amassed 20,000 ETH, worth just over $38 million at the time of writing.

Many eager buyers expressed their frustration over the minting experience, sharing how they were unable to obtain an Elemental NFT even though they were holders of Azuki or BEANZ NFTs. Some chalked it up to technical issues on the minting platform while others bemoaned the short minting window.

Chris Lepensky, data lead at DAO operations firm Utopia Labs, claimed that many Azuki holders were unable to mint due to “website errors and contract issues,” calling the experience “a major L.”

Location tba, one of the co-founders of Azuki and its parent company Chiru Labs, tweeted shortly after that the mint experience “was not up to the Azuki standard.”

“We underestimated the time needed for phase 1 and phase 2 of the presale for Azuki and BEANZ holders respectively,” they tweeted. “We should have extended the duration to more than 10 minutes to allow a sufficient buffer in the case of any issues (of which there were).”

Of the 10,000 NFTs available during the presale, 7,600 were minted by Azuki holders, while the rest were minted by BEANZ holders, they added.

“The team and I feel gutted over what happened,” location tba wrote.

Later on Tuesday, Azuki revealed the NFT artwork to holders, allowing them to trade on the secondary marketplace.