Simple game is good because it's easy to play. If you want to make a simple game then i will recommend you to make a game of life. It's simple easy to play and you can enjoy it. You can make your own story there like a novel.
Maybe it would be easier with making mods for existing games? Like I myself make maps for Warcraft 3 and Starcraft 2 (mostly as a hobby though) where I don't have to make my own assets and it's easy to get people to actually test your mod since you can borrow from the actual game community that are already involved. It obviously has it's drawbacks though, you can still make your own interfaces and stuff but you wouldn't make FPS or something.
When it comes to games like risk, I've always wanted a more generalised form of a Sengoku Rance like game where maps are customizable, and events are randomised (like monopoly pick a card events) or creatable/moddable. Examples: Sengoku Rance: Basic combat, where you have a set of units and they fight against enemy units. However, there can be a decent amount of strategy due to rock-paper-scissor and the like mechanics, and also other mechanics such as field effects and row guarding. What makes this game special is all the cool interesting events that can happen as you try and conquer the map, and a lot of the interesting events are collecting 'officers' that will fight for you. Pokemon Conquest: Here the fighting is based on SRPG mechanics, and there's a lot less content, but the game is still fun because of the default Risk like mechanics where you try and take over the map, and the 'conquest' combat bit can be fun/challenging if you find SRPGs fun. Each pokemon is an 'officer' unit, so you can have fun trying to collect them as well. Nobunaga's Ambition: More advanced fighting, but this game also adds a decent amount of 'base'/'city' building (if simplistic) mechanics, and also political things. Theoretically the combat could be anything, from a simple roll of a die, to a simple Brave Frontier like fight, to an interactive challenge you have to win - such as a tower building game blah blah. Anyway, point is the problem with all these games are that they get super boring if you play a few run throughs of them, as the map stays the same, the events stay the same etc etc.. They're also all Japanese so if you don't care about Japanese history, it gets boring as fk quick. I want a more generalised version, where maps can change, and there's a lot more randomised events akin to monopoly, and characters involved can be changed to suit the player. So overall: - Map of bases too be conquered. - Fun combat mechanic too conquer bases, ideally challenging. - Player/s aims will be to take over the map, and/or reach other win conditions. - Random events and triggers that can activate when you act that creates an overarching story. - Some can be from a generalised pool of events. - Others can be more integral to a story line. Some non-core features: - Officers and figureheads should matter, and be collectable and have strengths and weaknesses - there should be competition over the best. - City/Base building and general economy. - Political and spy actions, possibly things like 'eras' and 'policies' as well.