Average latency for the Lambda over the last week is 4.84s and it runs with 128mb of memory. Running every two minutes, that comes to ~25,000 invocations and ~15,000 GB-seconds of compute time per month. The AWS Lambda free usage tier includes 1M free requests per month and 400,000 GB-seconds of compute time per month so the Lambda is definitely free.
The website is tiny (homepage < 20kb excluding the thumbnails which are hosted by Twitch), so I'm also inside the free tier on S3 and CloudFront. I paid $12 upfront for the domain registration.