If you have only orthogonal walls, you can negate just the x- or y-component of the velocity (depending on whether you hit a horizontal or vertical wall), preserving the other.

Even though the game's resolution is super low and there's no obviously fancy surface shaders going on, the geometry/object count is pretty high. Normally that wouldn't be a problem but since the 1-bit rendering technique requires two passes, sending all the geometry to the GPU twice eats up a lot of frame time. Yesterday I decided to sit down and see if I could get all the rendering done in a single pass (plus post-processing). 

Are you changing the mesh geometry each frame? That's the only way you'd be sending a lot of stuff to the GPU. Mesh data resides on the GPU's memory after it's allocated by the driver. I'd say it's likely the slowdown was because of Unity dynamic batching breaking down due to your multi-pass shader, resulting in excessive draw calls.

Multi-pass shaders will break batching. Almost all unity shaders supports several lights in forward rendering, effectively doing additional pass for them. The draw calls for “additional per-pixel lights” will not be batched.

http://docs.unity3d.com/Manual/DrawCallBatching.html

That's only what teenagers think.

Unfortunately teenagers make up 90.23% of all yarrpeegee protagonists.

[Download]

Download
http://up.servut.us/dl/17667.aiz4ff

Inspiration
http://www.youtube.com/user/UncleSamPatriot

Why abandoned?
I suddenly got the idea to make a game out of the alter-ego of an insane YouTube denizen. The humour part must be incomprehensible to non-Finns but I'm sure the "INSANE EFFECTS" will keep one occupied for a second or two. It was fun to code, but I ran out of ideas and after every compile it became more and more boring to play. I should learn how to plan.

I think too much (in the most inconvenient way possible) and code too little.
Distractions.

I'm Yet Another Finn from the cold, reclusive northern part of Finland. I always sucked at games when I was little, so I preferred to watch my friends play. My life officially ended when my father hauled my first computer in from work, a Macintosh 128k. I moved on to PC somewhere during 2001 and home internet only reached me at 2003. So sad. :<
I've made games as a hobby for a long time, starting with KnP on a friend's PC before starting school. Last six years I've spent programming, mostly with a not-very-notorious Finnish game programming language called CoolBasic. I'm just too lazy to move on to anything better~