- See thru portals like in ASCIIPortal :
- Grab the mouse cursor and make mouse movement relative to Mario (so you keep aiming in the same direction even if you move, instead of changing directions to keep hitting the same point on the screen). This is closer to how mouse control works in most first person games.
- "Gravity gun". Using the portal gun, if you get close enough to a movable thing (weight cube, moving enemies etc) you can press E (use) and it will pick the thing up if you're aiming towards it. The scrollwheel rolls the object, and moving the mouse away from Mario moves the object away and viceversa (for this, grabbing the mouse cursor is also essential, otherwise things you grab would suddenly dart away if the cursor isn't at it when it's grabbed). You can't shoot portals while carrying somthing. If you grab a Bullet Bill you can re-aim it with the scroll wheel; and dropping an non-flying enemy upsidedown from a significant height (or if it gain speed from falling thru portals), if it's an enemy you can step on to kill, will kill it when it hits the ground topside first. Like with the "real" thing, you can't move things past a certain distance. I'm not clear on how the behavior should be regarding moving things behind obstacles, perhaps just break the hold and drop the object if there is enough solid thickness between Mario and the object being held?
edit: hm, it seems you can pick the cube and pretty much nothing else, but it doesn't work exactly like the gravity gun, is mostly just as if you were holding it with your own hands, can move it away nor anything...well, so this suggestion is about enhacing the functionality instead of creating it from scratch. - "Rotated" portals. By pressing a modifier key (perhaps the run key) portals you shoot will be "upside down", the orientation of things going coming out will be the opposite of the usual, and the component of the momentum that is parallel to the portal's "event horizon" for objects coming out will be flipped as well (unless of course the entry portal was also upside down; if both are upside down it's the same as if they are both right side up). Among other things this will allow you to make enemies come out upside down (and like above, if they fall from enough height, if they are stompable they die), and this will make it much easier to stay falling in an infinite loop (if you make opposite facing portals, even if you're not falling straight down, as long as you hit the bottom portal each time you come out above the horizontal component of your movement will be opposite to what it was the last time, canceling out and keeping you over the bottom portal.
Btw, perhaps the gravity gun needs to be one of the things you need to enable on the cheats menu instead of being avaiable by default since people might not expect such abilities to be present when designing levels?
