It's nice game and all, i really enjoyed it. However, after the completing the boss battle and starting extension mode (with extra spike types and challenge mode on) i came across a game breaking glitch. When i say game breaking, it didn't die on me, but it essentially ruined the game. First of all, i was forced to do the boss battle again and if i won it asked me about extension mode again. It was an endless cycle which i could only break by losing. I lost, respawned and got back to the level selection. Started on grasslands I, but the aura the boss gives stayed there and i couldn't be hit by any of the spikes, making the whole game pointless. I continued onto grasslands II, and the boss appeared and took the aura away with him, but he brought a new glitch. The spikes no longer fell, only the ground spike stayed working and the sound of the exploding spike is on a loop. Even as i've paused the game to write this, the ground spike is still attacking away and the exploding spikes r still goin. Plus, the screen as somehow moved itself up a little bit so theres a white space at the bottom.
I wasn't gonna bother reviewing the game until this happened but i see u've already fixed some bugs so i guess u'd be interested in knowin this one.