3D trailer is on Youtube:
https://www.youtube.com/watch?v=6-gpRtlnPak
They've also updated the site with some new info, here's the tl;dr:
-Stage select with high scores for each stage
-Save state
-Replay recording function with half-speed/double-speed playback
-Move with either the circle pad, d-pad or touch screen
-Supports Circle Pad Pro for use as a second throttle
-Button configs that let you invert the controls for the top-down sections, tap/hold toggle for the fire button, etc
-Five difficulty settings, including a new super-easy difficulty that removes environmental damage
-Adjustable lives stock (6 max, 3 default)
-On/off toggle for the "flight training" info
-Optional gyro controls that mimic pushing the stick on a real cabinet; includes both "tilt" and "rotation" configs
-Display options include original 4:3, 16:9, 16:10 (fullscreen) and virtual cabinet mode with moving housing; additionally, you can set the virtual cabinet mode to display the game in 2D but keep the cabinet/backgrounds in 3D
-Two backgrounds for virtual cabinet mode: an arcade BG and a city/skyscraper BG
-Volume settings for music/sfx/cabinet noises, plus an on/off toggle for cabinet noises
-Sound test with equaliser
-"Extra BGM" option that lets you listen to an arranged soundtrack (no idea if it's new or taken from some other port)
The big addition, however, is Special Mode! Unlocked by beating the last stage in the regular arcade mode, Special Mode includes the following features:
-New helicopter with altered handling and attack power; missiles will now travel along the ground instead of exploding on contact, allowing you to be more aggressive against ground enemies (I think? not familiar with the original game, so I don't know the context)
-New stage with a true last boss
-New enemy patterns and stage layouts
-New enemies not seen in arcade mode
-New title card/intro screens before each boss
-Different virtual cabinet displays with different movement parameters, environmental noises, etc
-Earn lives at the end of each stage based on your kill rate (again, not hugely familiar with the game, hopefully that makes sense in context); there are continues, but no stage select
There are probably some other smaller unlockables that'll be unveiled after the game's been out for a little while, like unlimited credits or extra cabinets/backgrounds, etc.