I just realized that #borderdown was made by #grev which makes a lot of sense. It's a really inventive #stg much like #kokuga. I may break out my Kokuga cart in a little bit. G.rev seems to go outside the #shmup boundaries a bit and I really like that.
#gradius v and #underdefeat are a bit more traditional but they're very fun games as well. I'll have to find some more G.rev titles I haven't tried yet.