I have discussed Dillon’s Dead Heat Breakers once, but I think even with my short time with the game It’s become my favorite 3DS game. It’s a lot of genres at once. There’s tower defense but there’s also action brawling, but there’s also combat racing? It also has multiple protagonists (your character, and Dillon) that you play as under different context.
It also does one of my favorite things I wish more videogames did and have a town that you hang out in between big missions. Here you can
1) Work at a store, which includes deciding what to stock, organizing the merchandise, and ringing up orders, it’s really fleshed out!
2) Play an approximation of Pachinko, including the part where you’re rewarded useless things that you then sell off to another NPC who is right next to the Pachinko games. This is actually kind of satisfying to play
3) A top down score attack shooter in the towns…VR Arcade?
4) And much more
The game itself has a Post Apocalyptic setting, but it isn’t like Mad Max or anything where “People are the real monsters” . you’re mainly fighting rock monsters from outer space and defending small towns and settlements outside the big city. Your character, a group of hired mercenaries, and Dylan, form a rag tag for hire defense team.

(I feel like now is a good time to mention that you, and every Mii you get in streetpass, gets turned into animals, which make up all the characters. This was a selling point, for me)
It also does another thing I wish more games did, where it abstracts what would normally be menu actions with physical actions in the game. You don’t have a turret “buy” phase before the mission, instead you walk around to other NPCs in a hotel bar and “hire” them based on the money you have. You don’t “end” the day, you walk up to your hotel room and go to bed. You return your haul after each mission to another shopkeeper. I think these actions really make you feel like you’re inhabiting the game world as your character. Azure Dreams also does this (I think) and so does Mega Man Legends.
The missions themselves have a lot going on, since you’re helping to defend towers by rolling around as Dylan, and addressing targets based on priority and position, but also maintaining power levels of the turrets. It can be overwhelming, it feels like they threw in the kitchen sink with this game, system wise. but it’s so unconventional that I really do enjoy it.
Sadly this game is Eshop only in the US, being released right next to the Switch in 2018, so it was criminally overlooked. This feels like the 3DS’s Ristar in terms of being a really good late-console title. I highly recommend getting it.
It’s weird and there’s a lot going on but it’s also pretty focused.