Game developer Chin Yong Kian, 30, was in reservist training about 18 months ago when he had a Eureka moment about creating a vertical platformer mobile game.

"While waiting for training to begin, I decided to try out some of the old-school games on my phone," said Mr Chin, who co-founded Rotten Mage, a game development studio that has made PC games such as Spacejacked.

What caught his eye then was the game Rapid Roll, in which gamers play as a ball rolling down platforms and have to avoid spikes. The simplicity of the game appealed to him.

"So I thought I would make a more intense version of that game with quirky characters and enemies," he said.

When his reservist training ended, he started developing this game in his free time. The game, called Serious Scramblers, was launched on the iOS App Store two weeks ago.

It is a retro vertical platformer game in which gamers play as a Ninja, a cat named Captain Ginger, a Poodle or a Rainbow Unicorn, and jump from one platform to another while avoiding obstacles and enemy creatures along the way.

Creating Serious Scramblers was no mean feat for Mr Chin as it was a personal project, which meant he had to juggle it with his work at Rotten Mage and being a part-time lecturer at the Republic Polytechnic.

He also developed the game almost entirely on his own, including creating the artwork of the characters and enemies. Only the game's icon artwork and music were outsourced. An artist friend whom he worked with when he was a student at the Digipen Institute of Technology Singapore (Digipen) created the icon artwork, while a Spanish composer whom he knew through Twitter composed the music.

"Throughout development, I made it a point to share my progress on Twitter to get valuable feedback," Mr Chin, who is single, said.

He revealed that for the first year, much of the game was developed during weekends. But in the subsequent six months, he started spending more time in the evenings every day to finish the game.

An avid gamer since he was young, he counts Metroid Fusion on the Nintendo Game Boy Advance as his favourite game. He started making games when he was introduced to the Macromedia Flash software during his secondary school days.

"I realised I could write codes in Flash to animate objects on screen. That got me really excited about making my own games," he said. He tried to make a pet simulator like Tamogotchi but failed. However, it was then that he decided he wanted to pursue games development.

After getting his diploma in Digital Entertainment Technology at Nanyang Polytechnic, he went on to study Computer Science at Digipen.

Upon graduation in 2013, he formed Rotten Mage with a few like-minded friends to make and sell games. He also started to teach game development last year.

But he continued to work on his personal projects like Serious Scramblers as "working on a personal project is a liberating experience and is great for unwinding".

"I suppose I need an outlet to express myself," Mr Chin said.