Professional quest is a game I've made in 2012.
It makes some kind of sense every now and then.
By the way the "engine" for this game is an .XML based system written for openframeworks.
It's quite generic an can be easily reused to create other games just by changing the assets and referencing them in the XML.
The XML itself contains the gameplay elements as a few nodes for the behaviours and conditions system, using a minimal kind of logid language in the attributes.
There is a few things that I like in this game :
I wanted to recreate the feeling of being lost in the game I had in a few Atari 2600 games such as Superman or Adventure.
You can take almost anything with you and carry it above your head as a single-slot inventory. Even buildings.
It's sometimes unclear if the view it top-down or with side flat layers.
A few non-euvclidian stuff.
One-button interaction : either it takes the thing, or use/enters it, or use the current carried item on the thing, or does nothing.
Attribute-based puzzles : instead of "use hatchet on Bruno to get the killer achievment" the game works by "use object tagged as killing on object tagged as alive to get the killer achievment".
That means despite feeling like an adventure game, it actually feels also like a mechanic-based game with choices, hidden things and several ways to solve puzzles, I love that.
Achievments rather than end-of-game goal, I still believe that's one of the few better response to the "getting stuck" problem than puzzle dependency charts (those charts kinda killed the fun in adventure games IMHO).