The HUD is constantly focus on your Hero with the option to examine other Heroes.Move modifiers stack via multiplication.Players can rejoin games they disconnect from, if you've ever played DotA you know why this is gameplay related.The map is smaller/faster, depending on your perspective, the map is either smaller or things move faster.There are 22 'new' Heroes, many of whom share only an ability or two with DotA heroes.So if you're looking for a gameplay difference, then they're few and far between. From Heroes, to items, right down to the default map, it is very much a DotA clone. So unlike League of Legends, Heroes of Newerth wasn't just designed to feel like DotA, but to actually be DotA.
