[Ruphin]

Very interesting. From playing a single game you immediately notice that traditional chess theory doesn't apply to this game at all. After some testing I found a few things in particular that change the way the game plays out drastically:

When having two pawns adjacent one of them can still defend the other by having it only slightly behind. They can also alternate defending each other with a single move. Pawns can also attack/defend things directly in front of them by pushing up against them. These things combined mean that it's almost impossible to have any pawn weaknesses, other than having a singled out pawn with no neighbors. In general pawns are the most improved piece with this ruleset.

The ability to move directly forward makes knights significantly stronger. Knights ability to move through other pieces is also particularly strong versus pawns which can now block most pieces from moving around quite easily.

Since pawns generally mainly move along one axis, it is easier to control the distance between pieces in the forward-backward axis than in the left-right axis. This makes it harder to utilise Rooks to capture two adjacent pieces. Bishops on the other hand have an easier time capturing two adjacent pieces, if positioned correctly. I'm not sure this compensates for the fact that bishops now have a much harder time penetrating positions, they are the most easily blocked of all the pieces.

Overall it is very interesting as a chess variant, it plays so very different from chess. It's hard to even figure out reasonable openers.