XenoBloom is a neat puzzle toy that you poke around with until you slowly unwrap its secrets. There is certainly the terrarium aspect with ecological balance, but there is also a zen-like feel I get from playing with one of those desktop sandscape panes.

And as a biogeochemist myself, I can tell you that there is certainly some cool science to consider here. This is a great primer on the flux of carbon and nutrients through different pools in the environment.

Essentially, you control the inputs and outputs of variables into a closed ecosystem. Things like carbon and nutrient pools, as well as water, sunlight, and even 'love'. Manipulating these variables 'feels' potent; the impact can be quite noticable. This is where the puzzle comes in. You tweak things to figure how they in-turn affect other things. While this title is small in scope, and your mileage may vary depending on how long mastery takes for you - it's all very fun.

Pros: +Quite fun to tinker with and slowly figure out how everything works and how things are connected +The 'hints' ease you into play nicely +It's neat to watch things grow and change +Local co-op! +The various modes are well chosen; the observation mode actually makes it a desktoy/screensaver which is great

Cons: -Your mileage will vary depending on how long it takes you to figure it all out, as well as how interested you are in managing/manipulating an ecosystem

Totally worth five bucks if this intrigues you.