Besiege is a devilishly simple, physics-based building game. You can create machines of destruction with ease. For a game in Alpha, it's surprising how polished Besiege feels. I was creating absurd death machines within a few of minutes. Sure, some of them weren't exactly structurally sound, often resulting in a horrid crumpled mess, but the process of iterating on a design is just so fulfilling that I didn't mind.