An army of humans laid waste to an alien colony as South African video game maker Simon Spreckley enthusiastically controlled the action using his phone's touch screen."The penetration of mobile devices in Africa is huge. People often have two or three phones, which is pretty crazy," said Spreckley, 40, who wore a T-shirt emblazoned with "Brute", a four-armed muscled alien from the game. "So that's one of the big pluses and why we are trying to do this," he said, promoting "Invasion Day" which will likely launch on Apple's App Store and Google's Play platform in 2019.The multi-player tactics game, set in the 1950s, is the brainchild of Spreckley's eight-strong team at VSUS, a Cape Town-based developer.Many other African developers are also opting to tailor games for mobile devices instead of traditional consoles like PlayStation or desktop computers, leading to a surge of handheld innovation on the continent. "There's enormous potential in Africa because the continent is primarily mobile," said Sidick Bakayoko, 34, the founder of Paradise Game, an umbrella group for developers in Ivory Coast."We've done a jump and instead of first going with PC, we've gone directly to mobile," he told AFP at last week's Africa Games Week convention in Cape Town which brought together African games coders, developers and artists with top executives from Sony and other industry giants."With the emergence of a number of low-cost smartphones, it's now very easy to purchase a mobile phone," he said while video games enthusiasts tried out the continent's latest digital offerings on screens nearby. 'Jump on the bandwagon' Bakayoko said that the increasing number of African gaming products for handheld devices mirrored the explosion of mobile banking and financial tools like Kenya's Mpesa on the continent in recent years."So there's great potential for video games using electronic payments... it can work well with Kenya as a prime example," he said."There's no reason for Africa not to jump on the bandwagon."Another part of mobile gaming's appeal over other platforms in Africa is that it consumes less data, which can be slow or costly."In Nigeria they even get games pre-loaded on the phones because data is so expensive," said Evan Greenwood, 37, the director of South Africa's leading computer game studio Free Lives."There's the potential (in Africa) -- but data has to get cheaper and the right games have to be made."Invasion Day will be free to download, but players must purchase upgrades from within the game.Spreckley hopes Invasion Day will catch the eye of a major investor, but many African mobile games developers have struggled to turn their creations into cash. 'In more people's hands' Ivory Coast's Point Point, based on a traditional children's game played using paper, and Madagascar's Gazkar, a racing game featuring the island's ubiquitous Citroen 2CV, have proved popular with mobile gamers -- though not readily profitable.But Google's decision in June to allow games developers from African countries including Nigeria, Zimbabwe, South Africa and Tanzania to make money from their creations sold on its Play store could revolutionise the sector."Most people use (Google) Android here," said Sithe Ncube, 24, the founder of Zambia's Ubongo Game Lab. "People haven't had a way to monetise their mobile games. People have actually been developing apps for a while but there hasn't been a way to use it as a business model," said Ncube who wore a spiked choker and had a streak of bright purple in her dark hair."If Google Play can let us do that, then that's a good platform for people to start on."In 2017, accountants PwC said "revenues for console and PC games will lose market share to social (and) casual gaming" like that offered on handheld devices.Africa's video game industry, currently worth $310 million, would be worth $642 million by 2021, the firm added.Spreckley said that choosing the mobile support for his game would mean "we can get it in more people's hands quicker"."You're not reliant on people buying big expensive consoles and then products off the shelf."