Decided to purchase the Metroidvania Mania Humble Bundle.
Ghost Song is in the bundle and tried it on Xbox when it was on GP and didn't find it too compelling, so for $2.50 it's available.
Axiom Verge so the key is available. - Edit, gone
As for the DG: Afterlife -AoV coupon, it's a 50% discount taking the DLC to $4. I'm going to install the base game now and try it out to see if I want it, but if someone really wants it lmkEdit - After playing the base game for a little I opted to just buy the DLC. I had tried this in early access when it was on GPU on my PC a number of years ago, so I was reminded of it and the improvements were enough for me to just buy the DLC.