So, I have a game idea in mind, and for that I need to record the game around the player. I'me not talking about recording it as video, but rather recording the scene objects, and their positions within the game, and then render them, giving the player the ability to go back and forth, to stop time and move around. I've made a prototype with some data structures in C#, since this is going to be the programming language we'll be using in our game, but if we want the player to be able to go back just five minutes back with the data of just 100 NPC's, it takes almost 1GB of RAM. Right now, I'm just storing a Doubly linked list, each item with the object position. In the game, I'll need to store even more data in each node, so I need something even more ligher. Of course, this algorithm is zero optimized, but still, that is a lot. The alternatives would be create the NPC's that aren't really important to the game when the user is viewing the past, but I don't really like it very much for the sake of realism. I wonder if there is a better way to store this? Thanks in advance, Scorch