So there you are, looking back at your creation. After months of programming, doing art, and/or animating, you finally did it. You've poured many of your time and effort in producing the game. It's time to release, but what is this? You are about to get the store page of your game ready for Steam but trailer is required? Bah! My game should speak for itself, and besides if I am to be a video editor, I would employ myself in an advertising agency might as well!
But admit it, you desire to showcase your game as much as possible. But before you think of buying Adobe Premiere, put back your maxed out credit card in your wallet and remember this.
A minute or less short
You're not making a movie or TV commercial so might as well use a software as simple as Movie Maker. Adobe Premiere is like using a chainsaw to cut a cheese in this case. For video capturing, you can use Camstudio or if you are lucky, like my new laptop comes with a free game recorder in its Xbox software, use that. Macs also come with iMovie for basic editing. You can also use open source OBS. Use whatever you have in your hands right now or get something free on the web, it's all fine. Now play your game normally and record it using any of the free softwares. Try doing impressive moves while recording your play so you can highlight it later in the trailer.
Concept is everything
You can go with anything, a trailer that is goofy, or epic or somewhat relaxing. With Tower Fortress, the concept was to promote it as a stress free game opening with a tagline, "Relax and play a game." Then it would show how frantic the game is which is quite the opposite... I know it's cheesy. So instead I just showed action footage and discarded the character select or upgrades. It's all about moving, jumping and shooting. In the end, I wanted to involve the viewer so I put back the audio and let the viewer see all these enemies and traps about to hit the character. I'm hoping the viewer would go, "Hey I can do that, I can kill this enemy first and then..." and it will be the hook to get the player try and buy the game.
Soundtrack takes the beat
When you think you have designers' block when you open up your Movie Maker, just drag the soundtrack to the dashboard and listen to it while watching your video clips. You will get a feel of the music beat and see there's pattern somewhere in your game that matches it. Start clipping and rearrranging them away! Use your soundtrack as your conductor and play along the music.
Here's the video trailer I made for Tower Fortress.