I've wanted to post about this again for a while, but it's non-inclusion in the IGF has given me motivation. I've still not been able to totally put my back into it, but it's the sort of game which strikes me is exactly what certain of you are looking for. It's a Sinistar-esque shooter, but with a sandbox design based around constructing your own ship from the parts of your fallen opponents. You can go and look at it here play the sort of limited demo, consider throwing down money for access to Captain Successor, but there's also some videos available which sort of show its vibe far better...
This one is a sped up version of more a sort of more-normal player. It's worth clicking through and seeing the discussion around the video, where people are talking about what the player is doing "wrong". Talking about your neat design and fiddling is part of the point.
This video shows the sort of monstrosity it is possible to build with a little (i.e. A lot) of dedication.
And this one shows someone sped-up burning right through the game, to show sort an efficient style of play.