REDDER (InstanceTopic, 17)
From Compile Worlds
REDDER is an indie Flash platformer with pretty basic gameplay. There's no upgrades to collect, your only moves are to run and jump, there are only a few level objects: exhaustively, red and green switchable blocks, robots that fly left and right, peashooters, pipes that reflect the bullets from the aforementioned peashooters, killer laser beams, checkpoints and collectible diamonds.
You're trying to collect the diamonds, but something's not quite right about doing that...
Thankfully, the author was kind enough to give you infinite lives, a short respawning animation and lots of checkpoints. You also get a map, which shows all the rooms you've explored, and where the diamonds you've seen but not collected are located.