Gunslugs is $1.99 PS+, $2.49 regular price, yup.
3D games are weird, because often times the better looking the 3D, the more generic it's art style, or simpler it's gameplay. I feel the same kind of "give and take" with "Total Recoil" and (other games you posted, I forget it's name!), in that they put one element forward, and another is more plain than I'd like.
3D gets cheaper (less expensive software, better quality free tools and assets), but as there are less and less 2D sprite artist out there than there were for the 2D focused eras, they seem to have become a premium due to scarcity.
Tribute Games and Zeboyd are the few I can think of that are small, yet consistently make games with better and better sprite work in each release. KOTANI on Yatagarasu actually worked on KoF, and even his small team seems like they were only able to make awesome character sprites, and had to skimp on the backgrounds, even with something like 4 / 6 years of dev on the game.
At least Orange Pixel's next game "
Heroes of Loot" (which is also coming to Vita, apparently) looks better than Gunslugs, and like they finally started to get more of a "style" to the in game art, even if it is still mostly simple. I think it can stand out on it's own, and goes past "bad programmer art" to being "competent, appealing, simple art".
When 2D was the norm, increased-quality graphics were demanded to stand out. Engines and gameplay were largely set, so they had to iterate artistically.
But now, just being 2D makes you stand out enough, and most smaller devs seem less interested in the art, and much more interested in getting a game out, and making an income, so they can try and make game development into their main moneymaker.
I wish we saw more 2D indies work like the "Arkedo" series, where they made games with appealing, well-realized styles, that were fairly simple, in a few weeks time, while still working on bigger, more ambitious titles. But considering how things turned out for them after Hell Yeah!....