I played a retro 2D platformer called "Castle in the Darkness" a few weeks ago and loved it! It's just like Simon's Quest on NES with 8-bit & 16-bit art as well as some homages to other classic titles. It honestly plays a lot like Shovel Knight, but it's a true open world like metroidvanias complete with save crystals and tons of boss fights.
I have to stress that the game is pretty hard if you aren't used to classic games. There are a lot of cheap spike trap deaths and the jumping/platforming is designed to be diabolical and cause you to die a lot. You will die a lot! I did, but I kept going and exploring because I was sucked into the game immediately and it seriously challenged me!
I really think that it is a better game than Shovel Knight, but I think Shovel Knight is more accessible and requires replays for grinding gold or whatever. Castle in the Darkness has a lot of secret wall and pathways and power ups that require you to backtrack to search for more hidden bosses and areas.
At the moment the game is only available on Steam, but watch for a sale during summer or holiday. It is worth checking out. Super hard though! Better come to consoles soon!
Alright, and that's my final BaD. Stay tuned for less frequent blog posts from me peeps! 
Due to Shovel Knight's popularity, we'll be seeing a lot of ripoffs. I think this year's Shovel Knight is going to be Adventures of Pip.
This looks pretty cool. I doubt I'd get very far in it though.
Looks like a good game, but I don't know how many more retro-fitted Steam titles I really need.
This looks like the games I grew up with, and I would be one of those players that would die a lot in these games.
I'll definitely check this out. I don't think I will ever get tired of these retro styled Metrovania type games. When you say it's like Simon's Quest does that mean it's cryptic as hell?
Yes. Parts are crypted.
Love those giant 2D 8-bit bosses!