RefleX is a vertically scrolling shoot’em up from Japan that has a lot going for it. There is a good quick pace between levels and frequent bosses. There is also a good shield mechanic that makes you defend and offend. If you have your shields out to bounce back bullets, they will drain, when they drain your gun power will drain until you stop using shields and guns, then your power will charge back up. Even with this simple mechanic it makes the game a lot of fun. It is of course bullet hell, but it feels approachable.