Day... four? (Aka I'm a delinquent)

After a few days of being very delinquent about blogging, and not getting much done because I've been going in without a plan, I want to be a real person again.  Here is what I want to do today:

0) a jump button, so that you don't jump with 'up' when gravity is flipped. No-brainer.
1) tile/character intersection, with the formula abs( p - tilePoint) <= radius --> intersection, where tilePoint is a point on the edge of the tile.
-----a) and then use it to implement wall collision rules. Iterate through all the tiles, and if they're a wall, check for collision. If collision... I haven't figured this bit out yet.
----------i) figure out what direction you're colliding from and put you at the edge of the previous tile
----------ii) check half your velocity and see if THAT'S a collision, and if not, move that distance; if yes, check half THAT velocity, etc. until you're getting to arbitrarily small numbers (like say, a pixel), then stop.
1.5) make a version of this that returns 'true' (i.e. intersection) once you're a little ways inside the tile, i.e. not exactly on the edge. I want to use this for picking up keys and for reaching the goal.
2) implement the goal, i.e., have moving into the goal square trigger a 'win!' message. (Later, this will trigger next level setup.)
3) spikes and death
-----a) spike sprites (facing N, E, S, W)
-----b) death function: character turns red and shrinks, then respawns. Use game time to manage the rate at which this all happens
----------i) note: dude needs a spawnPos property so that it knows where to respawn!

Okay, I feel like I have a plan. Onward and upward!