Loved it, great demo! Very solid and straight forward mechanics. Liked all the hidden areas, but I did jump down a few holes thinking they were hidden areas when they were actually just death pits.
Enemy design was fun, I loved the slide, and didn't feel a need for a free aim as the game was designed around only being able to shoot left / right, at least in this demo! Also liked how the flamethrower was used for small puzzle solving when it came to finding the right angle to burn the wood blocks.
Can't wait to see more!