Galaxy Collider 4+

It's quite a beautiful and rather accurate simulation of galaxy mergers. In answer to two other reviews of the current version, there is an option to increase or decrease the amount of time between each reset, along with allowing the simulation to run without reset.

Also, the disintegration of the galaxy occurs when the black holes at the centers of each galaxy merge and rocket into a random direction faster than escape velocity. This only happens in galaxy simulations with low or no dark matter halos.

Dark matter also effects the shape and rotation of the stars, themselves. Without DMH, the stars will rotate as in this simulation, swirling like water around the central black hole, with the outer stars rotating significantly more slowly than the inner stars. With the inclusion of DMH, the outer stars rotate at about the same rate as the inner stars due to the gravitational influence of the halo. This causes the spiral shape and stellar velocities that are actually observed in spiral galaxies.

Dark matter may also contribute to the shape or formation of central bulge in galaxies. Adding this feature (no idea how feasible from a coding standpoint) could potentially make this app more realistic that it even already is.

I love this app I personally find it very entertaining! I would, however, like more options such as a much higher particle limit, Galaxy thickness and type, The ability to change constants such as gravity, speed of light, etc... I have also come across whet I think is a bug. If you let the simulation run for a long time all of the stars just suddenly disintegrate :(.

The galaxies that i set were the largest possible, i tried two at first then progressively got to 5 at a time. It was pretty neat watching them collide with each other. One of the problems i think it has is that after a certain period of time elapsed the galaxies would reset whether or not they had collided yet or not. Also after they collide completely the entirety of each galaxy disappears. Not trying to bash this app, it is interesting and fun to play around with but it needs some fine tuning and additional settings to make me feel like i didn't just buy an app that i will uninstall and never use again. If anything get the lite version and play around on it for free.