I know venturing into the suggestions section is a foray commonly undertaken by those unfamiliar with forums, and generally results in horrible suggestions(Multiple Stickmen? Do those newfags know you can CONTROL stickman, that's like COD with each person playing 2 characters.).

On the topic of this post I will first address gravity. I mean REAL gravity(particle attraction, not moving solids), not idiot gravity that causes things to go down. I suggest that, like heat, you have the option to turn on gravity(See my "Environmental Variables" thread for a few ideas on what we should do with stuff like this). When gravity is on, dense particles with larger atomic weights attract to each other and form groups. This would work by causing each particle, depending on its weight, to generate a certain amount of negative pressure. Along with this, might I make a small suggestion along with this, being alterable gravity(1 being normal) and just multiplying the gravity value by the weight of each particle, that way it would require mostly GUI work to implement(though this suggestion is more optional).

For fusion, I suggest that under large amounts of pressure(positive pressing from outside or negative from inside) particles would "fuse", causing one to disappear and the other to reach max temperature instantly and release lightning-esque pressure. This could possibly be included in the Gravity toggle button.

I would just like to point out that by utilizing a toggle this wouldn't effect normal creations but would definitely allow for many space and star sims, reactors, engines, and other exciting creations(such as the much loved, you guesses it, BOMB).

I've gotten like thousands of pressure from lightning, and by high pressure I mean >100. And most the gravity suggestions are MOVABLE SOLIDS suggestions, which are bad. The point of fusion is it is a VERY powerful nuclear reaction, and I would love to see fusion reactors and star sims.

Well you could just change something in the core instead based on the weight for gravitation. And for changing the gravity, just multiply the weight value by the gravity value(Go from 5 to -5).