Bump games have been around since the 80s. Titles like Ys, Hydlide, SIlviana all focused on bump mechanics where you 'literally' run into the enemy. This is actually my 2nd bump game I made; the first one was for an NES Jam, though there are plenty enough differences between the two games.
As for the game size, it's 205,775 bytes (well, after it's patched). Seems a bit bloated, if you ask me... XD