Game Development

The "simplest of the simple" for your case might be developing in Javascript with something like Phaser, ImpactJS, PixiJS or MelonJS; BabylonJS if you want to try 3D. But these are frameworks, not proper engines, so you'll be doing a lot of coding, but at least what you make should run on any browser. One interesting thing to note is that older JS libraries like Impact^[The creator of Impact went on to make Q1K3, a "demake" of Quake in 13kb of javascript, which includes textures. Reading the "post-mortem" is an amazing look into size optimization] or KiwiJS aren't necessarily "worse", their main problem will be lack of support and learning material.

If you don't know programming, or if your skill is too low, take this opportunity to get better at it, learn to transform your idea into logical sequences that the computer understands. Learn programming, rely the least you can on external libraries and frameworks, and the engine and language become the least of your concerns, because you'll have a solid base to use any.