Chariot launched its game in May, backed by an adspend of £10 million. The company promised to benefit charities more than the National Lottery, but its website playlondon.com crashed on the first day and ticket sales were disappointing.
The new-media design agency Grasshopper, which created the front end of the Monday Lottery website, is also off the business and Chariot said this week that it has had conversations with other digital specialists.
Chariot lost its marketing director, Andrew Williams, in June. His resignation followed those of its chair-man, Tim Holley, the managing director, Craig Freeman, and the administrative director, David Gray.
A spokesman at Chariot said: "We are changing our creative direction in line with the new proposition more strongly focused online."
Chariot has cut the level of its payouts to charities, but managed to secure an extra £2.5 million in funding at the beginning of June.
A spokesman said: "We are a smaller company with a strong focus on our role as an online game. Our future strategy will reflect this."