Bakuretsu Muteki Bangai-O is one of my favourite games for the Dreamcast and may be Treasure's most under-rated game IMO. It's essentially a twin-stick shooter (once you swap the controls to ABXY) with a gravitational element a la Thrust but uses face buttons instead of a second stick like Super Smash TV on the SNES. As a side note, no the twin sticks peripheral doesn't work with this.
You have two characters to choose from which can be swapped between at any point, one of which fires homing rockets while the other fires ricocheting lasers. The levels - of which there are 44 IIRC - can get pretty intense and have some light puzzle elements too involving navigating falling blocks or utilising the properties of the 2 weapons. The real genius though is the special weapon. This releases a radial burst of missiles/lasers, the amount of which is proportional to how much danger you're immediately in. This encourages you to try and get into the middle of enemy fire to maximise this and when you release a 400-max burst, God damn is it satisfying. You can hold up to 5 of these in reserve and you recharge them by blowing shit up. While sometimes it may be best to kite and pick off enemies one by one, other times offence is very much the best form of defence and diving head first into a mass of enemies and utilising the special weapon is the better option.
A major aspect of the level design is destructible enemy spawners that if you let them, can completely fill the stage with bad guys. Some stages are actually quite small and can seem impossibly overwhelming if you're too cautious. The flip side is your special weapon charges extremely quickly because there's so many enemies so these stages are incredibly exhilirating once you get the hang of the game. Your hitbox is generous so with a bit of practise you can dance yourself into as dangerous a position as possible before unleashing Hell. You can take up to 8 hits but i-frames are limited so you can get destroyed almost instantly if you're careless. Causing great big fuck-off explosions usually spawns health pickups though so there's a great risk/reward system in play. The special weapon also often slows the game to a crawl as the poor Dreamcast struggles to render all the carnage. While this is a technical shortcoming, there's something that's actually quite rewarding about bringing the machine to its knees and almost feels intentional. Needless to say I love this game and think it's one great big adrenaline rush.